Post-Effective Amendment to Registration Statement by Investment Company (Form 485BPOS)

As filed with the Securities and Exchange Commission on September 26, 2025

File No. 333-30470

ICA No. 811-09815

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form N-1A

THE ARBITRAGE FUNDS

(Exact name of Registrant as Specified in Trust Instrument)

41 Madison Avenue

42^nd Floor

New York, New York 10010

(Address of Principal Executive Office)

(212) 584-2371

(Area Code and Telephone Number)

John S. Orrico

Water Island Capital, LLC

41 Madison Avenue, 42^nd Floor

New York, NY 10010

(Name and Address of Agent for Service)

Copy to:

Fatima Sulaiman, Esq.

K&L Gates LLP

1601 K Street, NW

Washington, D.C. 20006-1600

Approximate Date of Proposed Public Offering: Continuous.

It is proposed that this filing will become effective:

If appropriate, check the following box:

☐ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SEPTEMBER 26, 2025 | PROSPECTUS

ARBITRAGE FUND

Class R (Nasdaq Symbol: ARBFX)

Class I (Nasdaq Symbol: ARBNX)

Class C (Nasdaq Symbol: ARBCX)

Class A (Nasdaq Symbol: ARGAX)

WATER ISLAND EVENT-DRIVEN FUND

Class R (Nasdaq Symbol: AEDFX)

Class I (Nasdaq Symbol: AEDNX)

Class A (Nasdaq Symbol: AGEAX)

WATER ISLAND CREDIT OPPORTUNITIES FUND

Class R (Nasdaq Symbol: ARCFX)

Class I (Nasdaq Symbol: ACFIX)

Class A (Nasdaq Symbol: AGCAX)

104 Fifth Avenue, 9th Floor | New York, New York 10011

The Arbitrage Funds currently offers three fund series to investors - Arbitrage Fund, Water Island Event-Driven Fund and Water Island Credit Opportunities Fund (the "Funds"). Arbitrage Fund has four classes of shares (the "Classes") and Water Island Event-Driven Fund and Water Island Credit Opportunities Fund each have three Classes. The Classes differ only in the expenses and sales charges to which they are subject and with respect to investment eligibility requirements.

Arbitrage Fund seeks to achieve capital growth by engaging in merger arbitrage. Water Island Event-Driven Fund seeks to achieve capital growth. Water Island Credit Opportunities Fund seeks to provide current income and capital growth. The investment adviser to the Funds is Water Island Capital, LLC, 104 Fifth Avenue, 9th Floor, New York, New York 10011.

This prospectus contains information about the Funds that you should know before investing, including information about risks. Please read it carefully and keep it with your investment records.

The Securities and Exchange Commission has not approved or disapproved of these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

TABLE OF CONTENTS

No person has been authorized to give any information or to make any representations other than those contained in this prospectus and the Funds' Statement of Additional Information dated September 26, 2025 (which is incorporated by reference into this prospectus and is legally a part of this prospectus) and, if given or made, such information or representations may not be relied upon as having been authorized by us.

ARBITRAGE FUND

SUMMARY SECTION

Investment Objective

The Fund seeks to achieve capital growth by engaging in merger arbitrage.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may also pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below. You may qualify for sales charge discounts on Class A Shares if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund. More information about these and other discounts is available from your financial professional and in "How to Purchase Shares" beginning on page 42 of the statutory prospectus and in Appendix A to the prospectus, titled "Intermediary-Specific Sales Charge Reductions and Waivers."

Shareholder Fees (fees paid directly from your investment)

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

⁽¹⁾ ​This contingent deferred sales charge applies to Class C shares redeemed within 12 months of purchase.

⁽²⁾​ A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.

⁽³⁾ ​Acquired Fund Fees and Expenses are expenses incurred indirectly by the Fund through its ownership of shares in other investment companies.

⁽⁴⁾ ​The Total Annual Fund Operating Expenses in this fee table do not correlate to the expense ratio in the financial highlights because the expense ratios in the Financial Highlights do not reflect Acquired Fund Fees and Expenses.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Class C shares automatically convert to Class A shares approximately eight years after purchase if the conversion is available through your financial intermediary. This Example reflects your costs as though Class C shares were held for the full 10-year period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not

reflected in annual fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 162% of the average value of its portfolio.

Principal Investment Strategies

In attempting to achieve its investment objective, under normal market conditions the Fund will seek to invest at least 80% of its net assets (including borrowings for investment purposes) in equity securities of companies (both United States ((the "U.S.") and foreign) that are involved in publicly announced mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. Equity securities include common and preferred stock. The Fund may invest in equity securities of companies of any market capitalization. Merger arbitrage is a highly specialized investment approach designed to profit from the successful completion of mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. The Fund's investment adviser (the "Adviser") uses various investment strategies, including short selling and the purchasing and selling of options, in an attempt to preserve capital during times of market stress and to minimize market exposure, correlation, and volatility. The Adviser expects the Fund's assets to be invested across various industries; however, if for example, a large percentage (namely, at least 50%) of mergers or other corporate events taking place within the U.S. are within one industry over a given period of time, a large portion of the Fund's assets could be concentrated in that industry for that period of time.

The most common merger arbitrage activity, and the approach the Fund primarily uses, involves purchasing the shares of an announced acquisition target company at a discount to their expected value upon completion of the acquisition. The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the common stock of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities, as per the terms of the transaction, may be sold short. The purpose of the short sale is to protect against a decline in the market value of the acquiring company's securities prior to the acquisition's completion. The Fund may enter into equity swap agreements for the purpose of attempting to obtain a desired return on, or exposure to, certain equity securities or equity indices in an expedited manner or at a lower cost to the Fund than if the Fund had invested directly in such securities. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. Furthermore, the Fund may invest in other investment companies, including other funds advised by the Adviser, and in exchange traded funds ("ETFs").

The Fund generally engages in active and frequent trading of portfolio securities to achieve its investment objective. The Fund will generally sell or close out a security when the securities of the companies involved in the transaction no longer meet the Fund's expected return criteria when gauged by prevailing market prices and the relative risks of the situation. The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for defensive purposes, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. The Fund may also hold a significant amount of cash or short-term investments immediately after a period in which several transactions in which the Fund has invested close in a similar timeframe, yet before capital is redeployed to other opportunities.

Principal Risks

As with all mutual funds, investing in the Fund entails risks that could cause the Fund and you to lose money. The principal risks of investing in the Fund are as follows:

Merger Arbitrage Risk: The principal risk associated with the Fund's merger arbitrage investment strategy is that the proposed corporate reorganizations in which the Fund invests may not be completed or may be completed on less favorable terms than originally anticipated, in which case the Fund may realize losses.

Short Sale Risk: The Fund will suffer a loss if it sells a security short and the value of the security rises rather than falls. It is possible that the Fund's long positions will decline in value at the same time that the value of its short positions increase, thereby increasing potential losses to the Fund. Short sales expose the Fund to the risk that it will be required to buy the security sold short (also known as "covering" the short position) at a time when the security has appreciated in value, thus resulting in a loss to the Fund. The Fund's investment performance may also suffer if it is required to close out a short position earlier than it had intended. In addition, the Fund may be subject to expenses related to short sales that are not typically associated with investing in securities directly, such as costs of borrowing. These expenses may negatively impact the Fund's performance. When the Fund sells a security short, it must maintain cash or high-grade securities equal to the margin requirement. As a result, the Fund may maintain high levels of cash or other liquid assets (such as U.S. Treasury bills, money market instruments, certificates of deposit, high quality commercial paper and long equity positions). The need to maintain cash or other liquid assets could limit the Fund's ability to pursue other opportunities as they arise. Short positions introduce more risk to the Fund than long positions (purchases) because the maximum sustainable loss on a security purchased (held long) is limited to the amount paid for the security plus the transaction costs, whereas there is no maximum attainable price of the shorted security. Therefore, in theory, securities sold short have unlimited risk.

Active Management Risk: The Fund is an actively managed investment portfolio and is therefore subject to management risk. The Adviser will apply its investment and risk analysis in making investment decisions for the Fund, but there is no guarantee that these decisions will produce the intended results.

ARBITRAGE FUND

Concentration Risk: If a large percentage of mergers or other corporate events taking place within the U.S. are within one industry over a given period of time, the Fund may invest a large portion of its assets in securities of issuers in a single industry for that period of time. During such a period of concentration, the Fund may be subject to greater volatility with respect to its portfolio securities than a fund that is more broadly diversified.

High Portfolio Turnover Risk: The Fund normally expects to engage in active and frequent trading and expects to have a high portfolio turnover rate (over 100%). This may increase the Fund's brokerage commission costs, which would reduce performance. Rapid portfolio turnover also exposes shareholders to a higher current realization of short-term gains which could cause you to pay higher taxes.

Foreign Securities Risk: The securities of foreign issuers may be less liquid and more volatile than securities of comparable U.S. issuers. The costs associated with securities transactions may be higher in foreign countries than in the U.S. The U.S. dollar value of foreign securities traded in foreign currencies held by the Fund or by funds in which the Fund invests (and any dividends and interest earned) may be affected favorably or unfavorably by changes in foreign currency exchange rates. An increase in the U.S. dollar relative to these other currencies may adversely affect the Fund. Additionally, investments in foreign securities, even those publicly traded in the U.S., may involve risks which are in addition to those inherent in U.S. investments. Foreign companies may not be subject to the same regulatory requirements of U.S. companies, and as a consequence, there may be less publicly available information about such companies. Also, foreign companies may not be subject to uniform accounting, auditing, and financial reporting standards and requirements comparable to those applicable to U.S. companies. Foreign governments and foreign economies often are less stable than the U.S. Government and the U.S. economy.

Market Risk: Market risk is the possibility that securities prices will fluctuate over time, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an entire industry, or the market as a whole. Securities markets may experience short-term or even extended periods of heightened volatility and turmoil. These events could have an adverse effect on the value of the Fund's investments, and investors could lose money due to this price fluctuation. The value of a security may decline due to factors that are specifically related to a particular company, as well as general market conditions, such as real or perceived adverse economic or political conditions, inflation rates, changes in interest rates, or adverse investor sentiment. Geopolitical and other risks, including terrorism, war and sanctions, and environmental and public health risks (such as natural disasters, epidemics, and pandemics), may add to instability in world economies and markets generally. This uncertainty could lead to corporate events such as mergers, acquisitions, and restructurings breaking or forcing the Fund to allocate assets to other strategies. The extent and duration of such market disruptions cannot be predicted but could magnify the impact of other risks to the Fund, could adversely affect the Fund's investments, and could result in increased volatility of the Fund's net asset value.

Sector Risk: The securities of companies in the same or related businesses ("sectors"), if comprising a significant portion of the Fund's portfolio, may in some circumstances react negatively to market conditions, interest rates and economic, regulatory or financial developments, and may adversely affect the value of the Fund's portfolio, to a greater extent than if such securities comprised a lesser portion of the Fund's portfolio or if the Fund's portfolio was diversified across a greater number of sectors. Some sectors have particular risks that may not affect other sectors.

Derivatives Risk: In general, a derivative instrument typically involves leverage and provides exposure to potential gain or loss from a change in the market price of the underlying asset (or a basket of assets or an index) in a notional amount that exceeds the amount of cash or assets required to establish or maintain the derivative instrument. Adverse changes in the value or price of the underlying asset (or basket of assets or index), which the Fund may not directly own, can result in a loss to the Fund substantially greater than the amount invested in the derivative itself. The use of derivative instruments also exposes the Fund to additional risks and transaction costs. Derivative instruments come in many varieties and may include forward contracts, options (both written and purchased), and swap contracts.

Hedging Transaction Risk: The success of the Fund's hedging strategies will be subject to the Adviser's ability to assess correctly the degree of correlation between the performance of the instruments used in the hedging strategies and the performance of the investments in the Fund's portfolio being hedged. Hedging transactions involve the risk of imperfect correlation. Imperfect correlation may prevent the Fund from achieving the intended hedge or expose the Fund to risk of loss. Hedging transactions also limit the opportunity for gain if the value of a hedged portfolio position should increase.

Counterparty Risk: The Fund may enter into various types of derivative contracts with a counterparty that may be privately negotiated in the over-the-counter market. These contracts involve exposure to credit risk because contract performance depends, in part, on the financial condition of the counterparty. If a privately negotiated over-the-counter contract calls for payments by the Fund, the Fund must be prepared to make such payments when due. In addition, if the creditworthiness of the counterparty declines, the Fund may not receive payments owed under the contract, or such payments may be delayed and the value of agreements with the counterparty can be expected to decline, potentially resulting in losses to the Fund.

Temporary Investment/Cash Management Risk: The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash and cash equivalent positions, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

Swap Risk: The Fund may enter into swaps to gain investment exposure to the underlying security or securities in a more efficient or economically attractive manner than direct ownership. In a standard "swap" transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments. Certain categories of swap agreements often have terms of greater than seven days and may be considered illiquid. Moreover, the Fund bears the risk of loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. The swaps market is subject to extensive regulation under the Dodd-Frank Act and certain Securities and Exchange Commission and Commodity Futures Trading Commission rules promulgated thereunder. It is possible that developments in the swaps market, including new and additional government regulation, could result in higher Fund costs and expenses and could adversely affect the Fund's ability, among other things, to terminate existing swap agreements or to realize amounts to be received under such agreements.

Options Risk: Options transactions involve special risks that may make it difficult or impossible to close a position when the Fund desires. These risks include possible imperfect correlation between the price movements of the option and the underlying security; the potential lack of a liquid secondary market at any particular time; and possible price fluctuation limits. In addition, the option activities of the Fund may affect its portfolio turnover rate and the amount of brokerage commissions paid by the Fund.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell. Liquidity risk may be the result of, among other things, market turmoil, the reduced number and capacity of traditional market participants to make a market in fixed-income securities, or the lack of an active trading market. Markets for securities or financial instruments could be disrupted by a number of events, including, but not limited to, an economic crisis, natural disasters, new legislation, or regulatory changes inside or outside the U.S. Liquid investments may become less liquid after being purchased by the Fund, particularly during periods of market stress. To enhance investment value and/or protect shareholder rights, from time to time, the Fund may participate in various types of litigation, including but not limited to shareholder appraisal rights petitions and class action lawsuits. If the Fund exercises its appraisal rights, it may experience limited liquidity on its investment while the subject securities are being appraised. Illiquid and relatively less liquid investments may be harder to value, especially in turbulent markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss.

Investment Company and ETF Risk: Investing in securities issued by other investment companies, including ETFs, involves risks similar to those of investing directly in the securities and other assets held by the investment company or ETF. The Fund will indirectly bear its pro rata share of the fees and expenses incurred by a fund it invests in, including advisory fees. These expenses are in addition to the advisory and other expenses that the Fund bears directly in connection with its own operations. Unlike shares of typical mutual funds, shares of ETFs are traded on an exchange through a trading day and bought and sold based on market values and not at net asset value. For this reason, shares could trade either at a premium or a discount to net asset value. The trading price of an ETF is expected to closely track the actual net asset value of an ETF, and the Fund will generally gain or lose value consistent with the performance of the ETF's portfolio securities. The Fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs. An index-based ETF may not replicate exactly the performance of the benchmark index it seeks to track for a number of reasons, including transaction costs incurred by the ETF, the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting of securities or the number of securities held.

Leverage Risk: If the Fund uses leverage through activities such as borrowing, entering into short sales, purchasing securities on margin or on a "when-issued" basis or purchasing derivative instruments in an effort to increase its returns, the Fund has the risk of magnified capital losses that occur when losses affect an asset base, enlarged by borrowings or the creation of liabilities, that exceeds the net assets of the Fund. Should the Fund employ leverage, the Fund's net asset value may be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Small and Medium Capitalization Securities Risk: Securities issued by small and medium capitalization companies tend to be less liquid and more volatile than stocks of companies with relatively large market capitalizations. These securities may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, these small and medium sized companies may have limited product lines, markets, and financial resources, and may depend upon a relatively small management group.

Currency Risk: Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency-denominated investments and may widen any losses. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. The return of currency forward and futures contracts utilized for currency hedging may not perfectly offset the actual fluctuations of the foreign currencies relative to the U.S. dollar and may prevent the Fund from realizing gains from an increase in the value of the currency. In addition to currency risk, currency forward/futures contracts, like other derivatives, may be susceptible to credit risk and other risks.

Performance Information

The following information provides some indication of the risks and variability of investing in the Fund by showing how the Fund's performance has varied from year to year and by showing how the Fund's average annual returns for the past one-, five-, ten-year and since inception periods compare with those of the Standard & Poor's 500® Index, ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index.

ARBITRAGE FUND

The bar chart presents the calendar year total returns of the Fund's Class R Shares before taxes. Returns shown in the bar chart do not reflect sales charges applicable to other share classes, which would reduce performance results. The performance table reflects the performance of the Fund's Class R shares before and after taxes and the Fund's Class I, Class C and Class A shares before taxes. How the Fund has performed in the past (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated information on the Fund's performance can be obtained by visiting www.arbitragefunds.com.

Average Annual Total Returns for Periods Ended December 31, 2024

The table below shows the Fund's average annual total returns for Class R shares, Class I shares, Class C shares, and Class A shares compared with those of the Standard & Poor's 500® Index, ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index. The returns in the table below reflect the maximum applicable sales charges for the relevant share class. The table also presents the impact of taxes on the returns of the Fund's Class R shares. After-tax returns are shown for Class R shares only, and after-tax returns for Class I, Class C, and Class A shares will vary. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return after taxes on distributions measures the effect of taxable distributions, but assumes the underlying shares are held for the entire period. Return after taxes on distributions and sale of Fund shares shows the effect of both taxable distributions and any taxable gain or loss that would be realized if the underlying shares were purchased at the beginning and sold at the end of the period (for purposes of the calculation, it is assumed that income dividends and capital gain distributions are reinvested at net asset value and that the entire account is redeemed at the end of the period, including reinvested amounts).

Class C shares automatically convert to Class A shares approximately eight years after purchase if the conversion is available through your financial intermediary. In the table below, the performance for Class C shares does not reflect the conversion of Class C shares to Class A shares after eight years.

Average Annual Total Returns

* The inception date for Class R shares is September 18, 2000, the inception date for Class I shares is October 17, 2003, the inception date for Class C shares is June 1, 2012, and the inception date for the Class A shares is June 1, 2013. The "Since Inception" returns reflected for the Standard & Poor's 500^®​ Index, the ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index are based on the inception date for Class R shares.

** Due to new regulatory requirements, effective May 31, 2024, the Standard & Poor's 500^®​ Index became the Fund's broad-based securities market index. The Standard & Poor's 500^®​ Index serves as the Fund's regulatory index and provides a broad measure of market performance. The Standard and Poor's 500^®​ Index, or simply the S&P 500, is a stock market index tracking the performance of 500 large companies listed on stock exchanges in the U.S.

*** The ICE BofA U.S. 3-Month Treasury Bill Index tracks the performance of the U.S. Treasury Bills publicly issued in the U.S. domestic market with a remaining term to final maturity of less than 3 months.

**** The Bloomberg U.S. Aggregate Bond Index is a market value-weighted index of investment grade fixed-rated debt issues, including government, corporate, asset-backed and mortgage-backed securities with a maturity of one year or more.

The indexes are calculated on a total-return basis, are unmanaged and are not available for direct investment. The indexes reflect no deduction for fees, expenses, or taxes. The indexes are not intended to, and do not, parallel the risk or investment style of the Fund's investment strategy.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Return After Taxes on Distributions and Sale of Fund Shares to be greater than the Return After Taxes on Distributions or even the Return Before Taxes.

Investment Adviser

Water Island Capital, LLC is the investment adviser ("Adviser") of the Fund.

The Fund is team-managed, with multiple named portfolio managers working in cooperation with the additional members of the Adviser's investment team to make investment decisions for the Fund. While named portfolio managers are jointly and primarily responsible for the day-to-day management of the Fund, the Fund has also designated a lead portfolio manager who is ultimately responsible for managing the Fund in accordance with its investment objective(s) and strategies.

Portfolio Managers

Purchase and Sale of Fund Shares

Minimum Investment Amounts Class R Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

Minimum Investment Amounts Class I Shares - The minimum initial investment for all types of accounts is $100,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

You may conduct transactions by mail (Regular Mail to The Arbitrage Funds, c/o SS&C Global Investor and Distribution Solutions, Inc. ("SS&C GIDS"), P.O. Box 219842, Kansas City, Missouri 64121-9842, or Express/Overnight Mail to The Arbitrage Funds, c/o SS&C GIDS, 801 Pennsylvania Avenue, Suite 219842, Kansas City, Missouri 64105-1307), or by telephone at (800) 295-4485. Transactions will only occur on days the New York Stock Exchange ("NYSE") is open. Investors who wish to purchase, exchange, or redeem Class R or Class I shares through a broker-dealer should contact the broker-dealer regarding the hours during which orders to purchase, exchange, or sell shares of the Fund may be placed. The Fund's transfer agent is open from 9:00 a.m. to 5:00 p.m. Eastern Time for purchase, exchange, or redemption orders.

Minimum Investment Amounts Class C and Class A Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments in Class C or Class A shares.

Purchases, exchanges, and redemptions of Class C and Class A shares can be made only through institutional channels, such as financial intermediaries and retirement platforms, which have established an agreement with the Fund's distributor. Financial intermediaries may charge additional fees for their services, including ticket and/or transaction fees for processing trades. You should contact your financial intermediary or refer to your plan documents for information on how to invest in the Fund. Requests must be received in good order by the Fund or its agent (financial intermediary or plan sponsor, if applicable) prior to the close of the regular trading session of the NYSE in order to receive that day's net asset value.

Tax Information

The Fund's distributions are generally taxable as ordinary income or capital gains, unless you are investing through a tax-exempt or tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case such distributions may be taxable when withdrawn from such account.

ARBITRAGE FUND

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

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WATER ISLAND EVENT-DRIVEN FUND

SUMMARY SECTION

Investment Objective

The Fund seeks to achieve capital growth.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may also pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below. You may qualify for sales charge discounts on Class A Shares if you and your family invest, or agree to invest in the future, at least $100,000 in the Fund. More information about these and other discounts is available from your financial professional and in "How to Purchase Shares" beginning on page 42 of the statutory prospectus and in Appendix A to the prospectus, titled "Intermediary-Specific Sales Charge Reductions and Waivers."

Shareholder Fees (fees paid directly from your investment)

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

⁽¹⁾ ​A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.

⁽²⁾​ Acquired Fund Fees and Expenses are expenses incurred indirectly by the Fund through its ownership of shares in other investment companies.

⁽³⁾ ​The Fund has entered into an Amended and Restated Expense Waiver and Reimbursement Agreement with the Fund's Adviser pursuant to which the Adviser has contractually agreed to waive advisory fees and/or reimburse the Funds' other expenses to the extent that total operating expenses (exclusive of taxes, interest, dividends on short positions, brokerage commissions, acquired fund fees and expenses and other costs incurred in connection with the purchase or sale of portfolio securities) so that they do not exceed 1.69% of the Fund's average daily net assets allocable to the Class R shares, 1.44% of the Fund's average daily net assets allocable to the Class I shares, and 1.69% of the Fund's average daily net assets allocable to the Class A shares. The agreement remains in effect until September 30, 2026 unless terminated at an earlier time by the Fund's Board of Trustees. The Adviser may recoup any waived amount from the Fund pursuant to the agreement, if such recoupment does not cause the Fund to exceed expense limitations in effect at the time the amounts were waived, the recoupment does not cause the Fund to exceed the current expense limitation and the recoupment is done within three years after the date of the expense waiver.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver for the first year and equal to Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund's performance. During its most recent fiscal year, the Fund's portfolio turnover rate was 195% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests in equity and debt and debt-like instruments (including high yield bonds commonly known as "junk bonds") of companies whose prices the Fund's investment adviser (the "Adviser") believes are or will be impacted by a corporate event. Specifically, the Fund employs investment strategies designed to capture price movements generated by corporate events such as mergers, acquisitions, asset sales, restructurings, refinancings, recapitalizations, reorganizations, or other special situations (referred to as "event-driven opportunities"). The Fund may invest in both U.S. and foreign securities and may invest in securities of companies of any market capitalization and in debt securities of any maturity. The Fund may also invest in derivatives, such as options and swaps. Furthermore, the Fund may invest in exchange traded funds ("ETFs"). The Adviser expects the Fund's assets to be invested in various industries; however, if, for example, a large percentage (namely, at least 50%) of corporate events taking place within the U.S. are within one industry over a given period of time, a large portion of the Fund's assets could be concentrated in that industry for that period of time.

The Fund may utilize investment strategies such as merger arbitrage, convertible arbitrage, capital structure arbitrage, and special situations in order to profit from event-driven opportunities. These investment strategies are described more fully below.

Merger Arbitrage: Merger arbitrage is a highly specialized investment approach designed to profit from the successful completion of mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. The most common merger arbitrage activity, and the approach the Fund generally uses, involves purchasing the shares of an announced acquisition target company at a discount to their expected value upon completion of the acquisition. The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the securities of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities as per the terms of the transaction may be sold short.

Convertible Arbitrage: Convertible arbitrage is a specialized strategy that seeks to profit from pricing inefficiencies between a firm's convertible securities and its underlying equity. The most common convertible arbitrage approach, and the strategy the Fund generally uses, matches a long position in the convertible security with a short position in the underlying common stock. The Fund seeks to purchase convertible securities at discounts to their expected future values and sell short shares of the underlying common stock in order to mitigate equity market movements. As stock prices rise and the convertible security becomes more equity sensitive, the Fund may sell short additional common shares in order to maintain the relationship between the convertible and the underlying common stock. As stock prices fall, the Fund will typically buy back a portion of shares which it had sold short. Positions are typically designed to earn income from coupon or dividend payments and net gains from the purchase and sale of the convertible securities' positions and the underlying common stocks.

Capital Structure Arbitrage: Capital structure arbitrage seeks to profit from relative pricing discrepancies between related debt and/or equity securities. For example, when the Fund believes that unsecured securities are overvalued in relation to senior secured securities, the Fund may purchase a senior secured security of an issuer and sell short an unsecured security of the same issuer. In this example the trade would be profitable if credit quality spreads widened or if the issuer went bankrupt and the recovery rate for the senior debt was higher than anticipated. Another example might involve the Fund purchasing one class of common stock while selling short a different class of common stock of the same issuer. It is expected that, over time, the relative mispricing of the securities may decline, at which point the position will be liquidated.

Special Situations: The special situations strategy seeks to profit by investing in securities of companies whose stock price trades significantly higher or lower from where the Adviser believes they should trade, as the result of an ongoing or anticipated corporate catalyst. Corporate catalysts may include spin-offs, split-offs, asset sales, speculative mergers and acquisitions, transformational mergers and acquisitions, Dutch tenders (whereby an offer is made to purchase securities within a given price range through an auction structure, wherein shareholders are invited to sell shares over a specific time period by specifying the lowest price within the range that they will accept), regulatory changes, recapitalizations, refinancings, corporate levering/de-levering, un-solicited hostile offers, litigation, bankruptcy processes, distressed credit, and other catalysts. The strategy invests primarily in equity securities, but may also invest in debt, warrants, debentures, convertible securities, and preferred securities. The strategy may engage in short sales and derivatives to implement trading strategies and to mitigate volatility and market risk.

The Fund generally engages in active and frequent trading of portfolio securities to achieve its principal investment objective. The Fund may sell or close out a security when the securities of the companies involved in the transaction no longer meet the Fund's expected return criteria when gauged by prevailing market prices and the relative risks of the situation. The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for defensive purposes, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. The Fund may also hold a significant amount of cash or short-term investments immediately after a period in which several transactions in which the Fund has invested close in a similar timeframe, yet before capital is redeployed to other opportunities. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies.

WATER ISLAND EVENT-DRIVEN FUND

The Fund is non-diversified, which means that it may invest a greater portion of its assets in one or a limited number of issuers and may invest overall in a smaller number of issuers than a diversified fund.

Principal Risks

As with all mutual funds, investing in the Fund entails risks that could cause the Fund and you to lose money. The principal risks of investing in the Fund are as follows:

Merger Arbitrage Risk: The principal risk associated with the Fund's merger arbitrage investment strategy is that the proposed corporate reorganizations in which the Fund invests may not be completed or may be completed on less favorable terms than originally anticipated, in which case the Fund may realize losses.

Short Sale Risk: The Fund will suffer a loss if it sells a security short and the value of the security rises rather than falls. It is possible that the Fund's long positions will decline in value at the same time that the value of its short positions increases, thereby increasing potential losses to the Fund. Short sales expose the Fund to the risk that it will be required to buy the security sold short (also known as "covering" the short position) at a time when the security has appreciated in value, thus resulting in a loss to the Fund. The Fund's investment performance may also suffer if it is required to close out a short position earlier than it had intended. In addition, the Fund may be subject to expenses related to short sales that are not typically associated with investing in securities directly, such as costs of borrowing. These expenses may negatively impact the Fund's performance. When the Fund sells a security short, it must maintain cash or high-grade securities equal to the margin requirement. As a result, the Fund may maintain high levels of cash or other liquid assets (such as U.S. Treasury bills, money market instruments, certificates of deposit, high quality commercial paper, and long equity positions). The need to maintain cash or other liquid assets could limit the Fund's ability to pursue other opportunities as they arise. Short positions introduce more risk to the Fund than long positions (purchases) because the maximum sustainable loss on a security purchased (held long) is limited to the amount paid for the security plus the transaction costs, whereas there is no maximum attainable price of the shorted security. Therefore, in theory, securities sold short have unlimited risk.

Event-Driven Risk: Event-driven investments involve the risk that certain of the events driving the investment may not happen or the market may react differently than expected to the anticipated transaction. In addition, although an event may occur or is announced, it may be renegotiated, terminated, or involve a longer time frame than originally contemplated. Event-driven investment transactions are also subject to the risk of overall market movements. Any one of these risks could cause the Fund to experience investment losses, impacting its shares negatively.

Special Situations Risk: The Fund may seek to benefit from "special situations," such as mergers, acquisitions, consolidations, bankruptcies, liquidations, reorganizations, restructurings, tender or exchange offers, or other unusual events expected to affect a particular issuer. Investing in special situations carries the risk that certain of such situations may not happen as anticipated or the market may react differently than expected to such situations. The securities of companies involved in special situations may be more volatile than other securities, may at times be illiquid, or may be difficult to value. Certain special situations carry the additional risks inherent in difficult corporate transitions and the securities of such companies may be more likely to lose value than the securities of more stable companies.

Active Management Risk: The Fund is an actively managed investment portfolio and is therefore subject to management risk. The Adviser will apply its investment and risk analysis in making investment decisions for the Fund, but there is no guarantee that these decisions will produce the intended results.

Market Risk: Market risk is the possibility that securities prices will fluctuate over time, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an entire industry, or the market as a whole. Securities markets may experience short-term or even extended periods of heightened volatility and turmoil. These events could have an adverse effect on the value of the Fund's investments, and investors could lose money due to this price fluctuation. The value of a security may decline due to factors that are specifically related to a particular company, as well as general market conditions, such as real or perceived adverse economic or political conditions, inflation rates, changes in interest rates, or adverse investor sentiment. Geopolitical and other risks, including terrorism, war and sanctions, and environmental and public health risks (such as natural disasters, epidemics, and pandemics), may add to instability in world economies and markets generally. This uncertainty could lead to corporate events such as mergers, acquisitions, and restructurings breaking or forcing the Fund to allocate assets to other strategies. The extent and duration of such market disruptions cannot be predicted but could magnify the impact of other risks to the Fund, could adversely affect the Fund's investments, and could result in increased volatility of the Fund's net asset value.

Sector Risk: The securities of companies in the same or related businesses ("sectors"), if comprising a significant portion of the Fund's portfolio, may in some circumstances react negatively to market conditions, interest rates and economic, regulatory or financial developments, and may adversely affect the value of the Fund's portfolio, to a greater extent than if such securities comprised a lesser portion of the Fund's portfolio or if the Fund's portfolio was diversified across a greater number of sectors. Some sectors have particular risks that may not affect other sectors.

Hedging Transaction Risk: The success of the Fund's hedging strategies will be subject to the Adviser's ability to assess correctly the degree of correlation between the performance of the instruments used in the hedging strategies and the performance of the investments in the Fund's portfolio being hedged. Hedging transactions involve the risk of imperfect correlation. Imperfect correlation may prevent the Fund from achieving the intended hedge or expose the Fund to risk of loss. Hedging transactions also limit the opportunity for gain if the value of a hedged portfolio position should increase.

Derivatives Risk: In general, a derivative instrument typically involves leverage and provides exposure to potential gain or loss from a change in the market price of the underlying asset (or a basket of assets or an index) in a notional amount that exceeds the amount of cash or assets required to establish or maintain the derivative instrument. Adverse changes in the value or price of the underlying asset (or basket of assets or index), which the Fund may not directly own, can result in a loss to the Fund substantially greater than the amount invested in the derivative itself. The use of derivative instruments also exposes the Fund to additional risks and transaction costs. Derivative instruments come in many varieties and may include forward contracts, options (both written and purchased), and swap contracts.

Credit Risk: Credit risk refers to the possibility that the issuer of the security will not be able to make interest or principal payments when due. The Fund may invest in convertible and non-convertible debt securities, including high yield debt securities, also known as "junk bonds." Investments in junk bonds are subject to greater credit risks than securities with credit ratings above investment grade and have a greater risk of default than investment grade debt securities. Junk bonds are less sensitive to interest rate changes than higher credit quality instruments and generally are more sensitive to adverse economic changes or individual corporate developments.

Convertible Security Risk: Convertible securities generally offer lower interest or dividend yields than non-convertible securities of similar quality. Because convertible securities are higher in the firm's capital structure than equity, convertible securities are generally not as risky as the equity securities of the same issuer. However, convertible securities may gain or lose value due to changes in interest rates and other general economic conditions, industry fundamentals, market sentiment, and changes in the issuer's operating results and credit ratings.

Concentration Risk: If a large percentage of mergers or other corporate events taking place within the U.S. are within one industry over a given period of time, the Fund may invest a large portion of its assets in securities of issuers in a single industry for that period of time. During such a period of concentration, the Fund may be subject to greater volatility with respect to its portfolio securities than a fund that is more broadly diversified.

Non-Diversification Risk: The Fund is non-diversified, which means that it may invest a relatively high percentage of its assets in a limited number of issuers. As a result, the Fund's performance may be more vulnerable to changes in market value of a single issuer or group of issuers and more susceptible to risks associated with the occurrence of adverse events affecting a particular issuer than a diversified fund.

Counterparty Risk: The Fund may enter into various types of derivative contracts with a counterparty that may be privately negotiated in the over-the-counter market. These contracts involve exposure to credit risk because contract performance depends, in part, on the financial condition of the counterparty. If a privately negotiated over-the-counter contract calls for payments by the Fund, the Fund must be prepared to make such payments when due. In addition, if the creditworthiness of the counterparty declines, the Fund may not receive payments owed under the contract, or such payments may be delayed and the value of agreements with the counterparty can be expected to decline, potentially resulting in losses to the Fund.

Temporary Investment/Cash Management Risk: The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

High Portfolio Turnover Risk: The Fund normally expects to engage in active and frequent trading and expects to have a high portfolio turnover rate (over 100%). This may increase the Fund's brokerage commission costs, which would reduce performance. Rapid portfolio turnover also exposes shareholders to a higher current realization of short-term gains which could cause you to pay higher taxes.

Interest Rate Risk: Prices of debt securities and preferred stocks tend to move inversely with changes in interest rates. When interest rates fall, the market value of the respective debt securities and preferred securities usually increases. Conversely, when interest rates rise, the market value of the respective debt securities and preferred securities usually declines. As such, a change in interest rates may affect prices of the Fund's debt securities and preferred securities and, accordingly, the Fund's share price.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell. Liquidity risk may be the result of, among other things, market turmoil, the reduced number and capacity of traditional market participants to make a market in fixed-income securities, or the lack of an active trading market. Markets for securities or financial instruments could be disrupted by a number of events, including, but not limited to, an economic crisis, natural disasters, new legislation, or regulatory changes inside or outside the U.S. Liquid investments may become less liquid after being purchased by the Fund, particularly during periods of market stress. To enhance investment value and/or protect shareholder rights, from time to time, the Fund may participate in various types of litigation, including but not limited to shareholder appraisal rights petitions and class action lawsuits. If the Fund exercises its appraisal rights, it may experience limited liquidity on its investment while the subject securities are being appraised. Illiquid and relatively less liquid investments may be harder to value, especially in turbulent markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss.

WATER ISLAND EVENT-DRIVEN FUND

Options Risk: Options transactions involve special risks that may make it difficult or impossible to close a position when the Fund desires. These risks include possible imperfect correlation between the price movements of the option and the underlying security; the potential lack of a liquid secondary market at any particular time; and possible price fluctuation limits. In addition, the option activities of the Fund may affect its portfolio turnover rate and the amount of brokerage commissions paid by the Fund.

Swap Risk: The Fund may enter into swaps to gain investment exposure to the underlying security or securities in a more efficient or economically attractive manner than direct ownership. In a standard "swap" transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments. The Fund may also enter into credit default or credit default index swaps with qualified broker-dealer counterparties. In a credit default swap, one party typically makes an upfront payment and a stream of payments to another party in exchange for the right to receive a specified return in the event of a default by a referenced entity on its obligation or other credit-related event. The Fund may use swaps for any investment purpose, including as part of a merger arbitrage or event-driven strategy involving pending corporate reorganizations. Certain categories of swap agreements often have terms of greater than seven days and may be considered illiquid. Moreover, the Fund bears the risk of loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. The swaps market is subject to extensive regulation under the Dodd-Frank Act and certain Securities and Exchange Commission and Commodity Futures Trading Commission rules promulgated thereunder. It is possible that developments in the swaps market, including new and additional government regulation, could result in higher Fund costs and expenses and could adversely affect the Fund's ability, among other things, to terminate existing swap agreements or to realize amounts to be received under such agreements.

Small and Medium Capitalization Securities Risk: Securities issued by small and medium capitalization companies tend to be less liquid and more volatile than stocks of companies with relatively large market capitalizations. These securities may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, these small and medium sized companies may have limited product lines, markets, and financial resources, and may depend upon a relatively small management group.

Investment Company and ETF Risk: Investing in securities issued by other investment companies, including ETFs, involves risks similar to those of investing directly in the securities and other assets held by the investment company or ETF. The Fund will indirectly bear its pro rata share of the fees and expenses incurred by a fund it invests in, including advisory fees. These expenses are in addition to the advisory and other expenses that the Fund bears directly in connection with its own operations. Unlike shares of typical mutual funds, shares of ETFs are traded on an exchange through a trading day and bought and sold based on market values and not at net asset value. For this reason, shares could trade either at a premium or a discount to net asset value. The trading price of an ETF is expected to closely track the actual net asset value of an ETF, and the Fund will generally gain or lose value consistent with the performance of the ETF's portfolio securities. The Fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs. An index-based ETF may not replicate exactly the performance of the benchmark index it seeks to track for a number of reasons, including transaction costs incurred by the ETF, the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting of securities or the number of securities held.

Large Shareholder Transaction Risk: A significant percentage of the Fund's shares are owned or controlled by certain large shareholders, including another Fund advised by the Adviser. The Fund may experience adverse effects when certain large shareholders purchase or redeem large amounts of shares of the Fund. Such large shareholder redemptions may cause the Fund to sell its securities at times when it would not otherwise do so, which may negatively impact the Fund's NAV and liquidity. In addition, a large redemption could result in the Fund's current expenses being allocated over a smaller asset base, leading to an increase in the Fund's expense ratio. Similarly, large share purchases may adversely affect the Fund's performance to the extent that the Fund is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would.

Foreign Securities Risk: The securities of foreign issuers may be less liquid and more volatile than securities of comparable U.S. issuers. The costs associated with securities transactions may be higher in foreign countries than in the U.S. The U.S. dollar value of foreign securities traded in foreign currencies held by the Fund or by funds in which the Fund invests (and any dividends and interest earned) may be affected favorably or unfavorably by changes in foreign currency exchange rates. An increase in the U.S. dollar relative to these other currencies may adversely affect the Fund. Additionally, investments in foreign securities, even those publicly traded in the U.S., may involve risks which are in addition to those inherent in U.S. investments. Foreign companies may not be subject to the same regulatory requirements of U.S. companies, and as a consequence, there may be less publicly available information about such companies. Also, foreign companies may not be subject to uniform accounting, auditing, and financial reporting standards and requirements comparable to those applicable to U.S. companies. Foreign governments and foreign economies often are less stable than the U.S. Government and the U.S. economy.

Leverage Risk: If the Fund uses leverage through activities such as borrowing, entering into short sales, purchasing securities on margin or on a "when-issued" basis or purchasing derivative instruments in an effort to increase its returns, the Fund has the risk of magnified capital losses that occur when losses affect an asset base, enlarged by borrowings or the creation of liabilities, that exceeds the net assets of the Fund. Should the Fund employ leverage, the Fund's net asset value may be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Currency Risk: Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency denominated investments and may widen any losses. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. The return of currency forward and

futures contracts utilized for currency hedging may not perfectly offset the actual fluctuations of the foreign currencies relative to the U.S. dollar and may prevent the Fund from realizing gains from an increase in the value of the currency. In addition to currency risk, currency forward/futures contracts, like other derivatives, may be susceptible to credit risk and other risks.

Performance Information

The following information provides some indication of the risks and variability of investing in the Fund by showing how the Fund's performance has varied from year to year and by showing how the Fund's average annual returns for the past one-, five-, ten-year and since inception periods compare with those of the Standard & Poor's 500® Index, ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index.

The bar chart presents the calendar year total returns of the Fund's Class R Shares before taxes. Returns shown in the bar chart do not reflect sales charges applicable to other share classes, which would reduce performance results. The performance table reflects the performance of the Fund's Class R shares before and after taxes and the Fund's Class I and Class A shares before taxes. How the Fund has performed in the past (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Performance reflects fee waivers in effect. If fee waivers were not in place, the Fund's performance would be reduced. Updated information on the Fund's performance can be obtained by visiting www.arbitragefunds.com.

Average Annual Total Returns for Periods Ended December 31, 2024

The table below shows the Fund's average annual total returns for Class R shares, Class I shares, and Class A shares compared with those of the Standard & Poor's 500® Index, ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index. The returns in the table below reflect the maximum applicable sales charges for the relevant share class. The table also presents the impact of taxes on the returns of the Fund's Class R shares. After-tax returns are shown for Class R shares only, and after-tax returns for Class I and Class A shares will vary. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return after taxes on distributions measures the effect of taxable distributions, but assumes the underlying shares are held for the entire period. Return after taxes on distributions and sale of Fund shares shows the effect of both taxable distributions and any taxable gain or loss that would be realized if the underlying shares were purchased at the beginning and sold at the end of the period (for purposes of the calculation, it is assumed that income dividends and capital gain distributions are reinvested at net asset value and that the entire account is redeemed at the end of the period, including reinvested amounts).

Average Annual Total Returns

WATER ISLAND EVENT-DRIVEN FUND

* The inception date for Class R shares and Class I shares is October 1, 2010 and the inception date for the Class A shares is June 1, 2013. The "Since Inception" returns reflected for the Standard & Poor's 500^®​ Index, the ICE BofA U.S. 3-Month Treasury Bill Index and the Bloomberg U.S. Aggregate Bond Index are based on the inception date for Class R shares.

** Due to new regulatory requirements, effective May 31, 2024, the Standard & Poor's 500^®​ Index became the Fund's broad-based securities market index. The Standard & Poor's 500^®​ Index serves as the Fund's regulatory index and provides a broad measure of market performance. The Standard and Poor's 500^®​ Index, or simply the S&P 500, is a stock market index tracking the performance of 500 large companies listed on stock exchanges in the U.S.

*** The ICE BofA U.S. 3-Month Treasury Bill Index tracks the performance of the U.S. Treasury Bills publicly issued in the U.S. domestic market with a remaining term to final maturity of less than 3 months.

**** The Bloomberg U.S. Aggregate Bond Index is a market value-weighted index of investment grade fixed-rated debt issues, including government, corporate, asset-backed and mortgage-backed securities with a maturity of one year or more.

The indexes are calculated on a total-return basis, are unmanaged and are not available for direct investment. The indexes reflect no deduction for fees, expenses, or taxes. The indexes are not intended to, and do not, parallel the risk or investment style of the Fund's investment strategy.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Return After Taxes on Distributions and Sale of Fund Shares to be greater than the Return After Taxes on Distributions or even the Return Before Taxes.

Investment Adviser

Water Island Capital, LLC is the investment adviser ("Adviser") of the Fund.

The Fund is team-managed, with multiple named portfolio managers working in cooperation with the additional members of the Adviser's investment team to make investment decisions for the Fund. While named portfolio managers are jointly and primarily responsible for the day-to-day management of the Fund, the Fund has also designated a lead portfolio manager who is ultimately responsible for managing the Fund in accordance with its investment objective(s) and strategies.

Portfolio Managers

Purchase and Sale of Fund Shares

Minimum Investment Amounts Class R Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

Minimum Investment Amounts Class I Shares - The minimum initial investment for all types of accounts is $100,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

You may conduct transactions by mail (Regular Mail to The Arbitrage Funds, c/o SS&C GIDS, P.O. Box 219842, Kansas City, Missouri 64121-9842, or Express/Overnight Mail to The Arbitrage Funds, c/o SS&C GIDS, 801 Pennsylvania Avenue, Suite 219842, Kansas City, Missouri 64105), or by telephone at (800) 295-4485. Transactions will only occur on days the New York Stock Exchange ("NYSE") is open. Investors who wish to purchase, exchange, or redeem Class R or Class I shares through a broker-dealer should contact the broker-dealer regarding the hours during which orders to purchase, exchange, or sell shares of the Fund may be placed. The Fund's transfer agent is open from 9:00 a.m. to 5:00 p.m. Eastern Time for purchase, exchange, or redemption orders.

Minimum Investment Amounts Class A Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments.

Purchases, exchanges, and redemptions of Class A shares can be made only through institutional channels, such as financial intermediaries and retirement platforms, which have established an agreement with the Fund's distributor. Financial intermediaries may charge additional fees for their services, including ticket and/or transaction fees for processing trades. You should contact your financial intermediary or refer to your plan documents for information on how to invest in the Fund. Requests must be received in good order by the Fund or its agent (financial intermediary or plan sponsor, if applicable) prior to the close of the regular trading session of the NYSE in order to receive that day's net asset value.

Tax Information

The Fund's distributions are generally taxable as ordinary income or capital gains, unless you are investing through a tax-exempt or tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case such distributions may be taxable when withdrawn from such account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

WATER ISLAND CREDIT OPPORTUNITIES FUND

SUMMARY SECTION

Investment Objective

The Fund seeks to provide current income and capital growth.

Fund Fees and Expenses

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may also pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below. You may qualify for sales charge discounts on Class A Shares if you and your family invest, or agree to invest in the future, at least $100,000 in the Fund. More information about these and other discounts is available from your financial professional and in "How to Purchase Shares" beginning on page 42 of the statutory prospectus and in Appendix A to the prospectus, titled "Intermediary-Specific Sales Charge Reductions and Waivers."

Shareholder Fees (fees paid directly from your investment)

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

⁽¹⁾ ​A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.

⁽²⁾​ Acquired Fund Fees and Expenses are expenses incurred indirectly by the Fund through its ownership of shares in other investment companies.

⁽³⁾ ​The Fund has entered into an Amended and Restated Expense Waiver and Reimbursement Agreement with the Fund's Adviser pursuant to which the Adviser has contractually agreed to waive advisory fees and/or reimburse the Funds' other expenses to the extent that total operating expenses (exclusive of taxes, interest, dividends on short positions, brokerage commissions, acquired fund fees and expenses and other costs incurred in connection with the purchase or sale of portfolio securities) so that they do not exceed 1.23% of the Fund's average daily net assets allocable to the Class R shares, 0.98% of the Fund's average daily net assets allocable to the Class I shares, and 1.23% of the Fund's average daily net assets allocable to the Class A shares. The agreement remains in effect until September 30, 2026 unless terminated at an earlier time by the Fund's Board of Trustees. The Adviser may recoup any waived amount from the Fund pursuant to the agreement, if such recoupment does not cause the Fund to exceed expense limitations in effect at the time the amounts were waived, the recoupment does not cause the Fund to exceed the current expense limitation and the recoupment is done within three years after the date of the expense waiver.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's expenses are equal to the Total Annual Fund Operating Expenses After Fee Waiver for the first year and equal to the Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 132% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests primarily in a portfolio of debt securities including corporate bonds and debentures (including high yield bonds commonly known as "junk bonds"), bank loans, convertible and preferred securities, credit default swaps and other debt instruments and derivatives that the Fund's investment adviser (the "Adviser") believes have debt-like characteristics. The Fund invests in both U.S. and foreign debt securities. The principal types of derivatives in which the Fund may invest are credit default swaps, interest rate swaps, equity swaps, futures, and options.

The Fund invests primarily in debt securities whose returns the Adviser believes will be more correlated with the outcome of specific catalysts or events rather than overall market direction. These catalysts and events include mergers, acquisitions, debt maturities, refinancings, regulatory changes, recapitalizations, reorganizations, restructurings, and other special situations. The Fund also uses a relative value approach and may express positive views on specific issuers by taking long positions in cash bonds and/or derivatives and negative views on specific issuers by taking short positions in cash bonds and/or derivatives. The Fund uses fundamental research to identify mispricings or inefficiencies in these situations and assesses their potential impact on security prices.

The Fund may engage in short-term trading strategies and may engage in short sales and invest in derivatives. The principal short-term trading strategies may at times include convertible arbitrage, merger arbitrage, and capital structure arbitrage, which are discussed below. The Fund may seek to mitigate the risk of volatility (the appreciation or depreciation of the value of a security over a period of time) and duration (the impact of interest rate changes on fixed-income securities) by engaging in short sales and/or investing in derivatives, including credit default swaps, interest rate swaps, futures, and options. The Fund may purchase or sell short equity securities or derivatives as part of a hedging strategy or hold equity positions or other assets that the Fund receives as part of a reorganization process. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. Furthermore, the Fund may invest in exchange traded funds ("ETFs").

The Fund is not limited with respect to its portfolio maturity or duration. The Fund may invest in debt securities without regard to their credit ratings, including securities that are unrated, and in debt securities with a wide variety of terms that may vary from security to security, including but not limited to optional and mandatory prepayment provisions, fixed, variable, semi-variable, and resettable interest rates and conversion options, as well as various combinations of these terms. The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for defensive purposes, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. The Fund may also hold a significant amount of cash or short-term investments immediately after a period in which several transactions in which the Fund has invested close in a similar timeframe, yet before capital is redeployed to other opportunities.

Merger Arbitrage: Merger arbitrage is a highly specialized investment approach designed to profit from the successful completion of mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. The most common merger arbitrage activity, and the approach the Fund generally uses, involves purchasing debt securities of an announced acquisition target company at a discount to their expected value upon completion of the acquisition. The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the securities of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities as per the terms of the transaction may be sold short.

Convertible Arbitrage: Convertible arbitrage is a specialized strategy that seeks to profit from pricing inefficiencies between a firm's convertible securities and its underlying equity. The most common convertible arbitrage approach, and the strategy the Fund generally uses, matches a long position in the convertible security with a short position in the underlying common stock. The Fund seeks to purchase convertible securities at discounts to their expected future values and sell short shares of the underlying common stock in order to mitigate equity market movements. As stock prices rise and the convertible security becomes more equity sensitive, the Fund may sell short additional common shares in order to maintain the relationship between the convertible and the underlying common stock. As stock prices fall, the Fund will typically buy back a portion of shares which it had sold short. Positions are typically designed to earn income from coupon or dividend payments and net gains from the purchase and sale of the convertible securities' positions and the underlying common stocks.

Capital Structure Arbitrage: Capital structure arbitrage seeks to profit from relative pricing discrepancies between related debt and/or equity securities. For example, when the Fund believes that unsecured securities are overvalued in relation to senior secured securities, the Fund may purchase a senior secured security of an issuer and sell short an unsecured security of the same issuer. In this example the trade would be profitable if credit quality spreads widened or if the issuer went bankrupt and the recovery rate for the senior debt was higher than anticipated. It is expected that, over time, the relative mispricing of the securities may decline, at which point the position will be liquidated.

WATER ISLAND CREDIT OPPORTUNITIES FUND

Principal Risks

As with all mutual funds, investing in the Fund entails risks that could cause the Fund and you to lose money. The principal risks of investing in the Fund are as follows:

Event-Driven Risk: Event-driven investments involve the risk that certain of the events driving the investment may not happen or the market may react differently than expected to the anticipated transaction. In addition, although an event may occur or is announced, it may be renegotiated, terminated, or involve a longer time frame than originally contemplated. Event-driven investment transactions are also subject to the risk of overall market movements. Any one of these risks could cause the Fund to experience investment losses, impacting its shares negatively.

Merger Arbitrage Risk: The principal risk associated with the Fund's merger arbitrage investment strategy is that the proposed corporate reorganizations in which the Fund invests may not be completed or may be completed on less favorable terms than originally anticipated, in which case the Fund may realize losses.

Active Management Risk: The Fund is an actively managed investment portfolio and is therefore subject to management risk. The Adviser will apply its investment and risk analysis in making investment decisions for the Fund, but there is no guarantee that these decisions will produce the intended results.

Credit Risk: Credit risk refers to the possibility that the issuer of the security will not be able to make interest or principal payments when due. The Fund may invest in convertible and non-convertible debt securities, including high yield debt securities, also known as "junk bonds." Investments in junk bonds are subject to greater credit risks than securities with credit ratings above investment grade and have a greater risk of default than investment grade debt securities. Junk bonds are less sensitive to interest rate changes than higher credit quality instruments and generally are more sensitive to adverse economic changes or individual corporate developments.

Convertible Security Risk: Convertible securities generally offer lower interest or dividend yields than non-convertible securities of similar quality. Because convertible securities are higher in the firm's capital structure than equity, convertible securities are generally not as risky as the equity securities of the same issuer. However, convertible securities may gain or lose value due to changes in interest rates and other general economic conditions, industry fundamentals, market sentiment and changes in the issuer's operating results and credit ratings.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell. Liquidity risk may be the result of, among other things, market turmoil, the reduced number and capacity of traditional market participants to make a market in fixed-income securities, or the lack of an active market. Markets for securities or financial instruments could be disrupted by a number of events, including, but not limited to, an economic crisis, natural disasters, new legislation or regulatory changes inside or outside the U.S. Liquid investments may become less liquid after being purchased by the Fund, particularly during periods of market stress. Illiquid and relatively less liquid investments may be harder to value, especially in turbulent markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss.

Market Risk: Market risk is the possibility that securities prices will fluctuate over time, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an entire industry, or the market as a whole. Securities markets may experience short-term or even extended periods of heightened volatility and turmoil. These events could have an adverse effect on the value of the Fund's investments, and investors could lose money due to this price fluctuation. The value of a security may decline due to factors that are specifically related to a particular company, as well as general market conditions, such as real or perceived adverse economic or political conditions, inflation rates, changes in interest rates, or adverse investor sentiment. Geopolitical and other risks, including terrorism, war and sanctions, and environmental and public health risks (such as natural disasters, epidemics, and pandemics), may add to instability in world economies and markets generally. This uncertainty could lead to corporate events such as mergers, acquisitions, and restructurings breaking or forcing the Fund to allocate assets to other strategies. The extent and duration of such market disruptions cannot be predicted but could magnify the impact of other risks to the Fund, could adversely affect the Fund's investments, and could result in increased volatility of the Fund's net asset value.

Sector Risk: The securities of companies in the same or related businesses ("sectors"), if comprising a significant portion of the Fund's portfolio, may in some circumstances react negatively to market conditions, interest rates and economic, regulatory or financial developments, and may adversely affect the value of the Fund's portfolio, to a greater extent than if such securities comprised a lesser portion of the Fund's portfolio or if the Fund's portfolio was diversified across a greater number of sectors. Some sectors have particular risks that may not affect other sectors.

Interest Rate Risk: Prices of debt securities and preferred stocks tend to move inversely with changes in interest rates. When interest rates fall, the market value of the respective debt securities and preferred securities usually increases. Conversely, when interest rates rise, the market value of the respective debt securities and preferred securities usually declines. As such, a change in interest rates may affect prices of the Fund's debt securities and preferred securities and, accordingly, the Fund's share price.

Short Sale Risk: The Fund will suffer a loss if it sells a security short and the value of the security rises rather than falls. It is possible that the Fund's long positions will decline in value at the same time that the value of its short positions increase, thereby increasing potential losses to the Fund. Short sales expose the Fund to the risk that it will be required to buy the security sold short (also known as "covering" the short position) at a time when the security has appreciated in value, thus resulting in a loss to the Fund. The Fund's investment performance may also suffer if it is required to close out a short position earlier than it had intended. In addition, the Fund may be subject to expenses related to short sales that are not typically associated

with investing in securities directly, such as costs of borrowing. These expenses may negatively impact the Fund's performance. When the Fund sells a security short, it must maintain cash or high-grade securities equal to the margin requirement. As a result, the Fund may maintain high levels of cash or other liquid assets (such as U.S. Treasury bills, money market instruments, certificates of deposit, high quality commercial paper, and long equity positions). The need to maintain cash or other liquid assets could limit the Fund's ability to pursue other opportunities as they arise. Short positions introduce more risk to the Fund than long positions (purchases) because the maximum sustainable loss on a security purchased (held long) is limited to the amount paid for the security plus the transaction costs, whereas there is no maximum attainable price of the shorted security. Therefore, in theory, securities sold short have unlimited risk.

Hedging Transaction Risk: The success of the Fund's hedging strategies will be subject to the Adviser's ability to assess correctly the degree of correlation between the performance of the instruments used in the hedging strategies and the performance of the investments in the Fund's portfolio being hedged. Hedging transactions involve the risk of imperfect correlation. Imperfect correlation may prevent the Fund from achieving the intended hedge or expose the Fund to risk of loss. Hedging transactions also limit the opportunity for gain if the value of a hedged portfolio position should increase.

Large Shareholder Transaction Risk: A significant percentage of the Fund's shares may be owned or controlled by certain large shareholders. The Fund may experience adverse effects when certain large shareholders purchase or redeem large amounts of shares of the Fund. Such large shareholder redemptions may cause the Fund to sell its securities at times when it would not otherwise do so, which may negatively impact the Fund's NAV and liquidity. In addition, a large redemption could result in the Fund's current expenses being allocated over a smaller asset base, leading to an increase in the Fund's expense ratio. Similarly, large share purchases may adversely affect the Fund's performance to the extent that the Fund is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would.

Leverage Risk: If the Fund uses leverage through activities such as borrowing, entering into short sales, purchasing securities on margin or on a "when-issued" basis or purchasing derivative instruments in an effort to increase its returns, the Fund has the risk of magnified capital losses that occur when losses affect an asset base, enlarged by borrowings or the creation of liabilities, that exceeds the net assets of the Fund. Should the Fund employ leverage, the Fund's net asset value may be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

High Portfolio Turnover Risk: The Fund normally expects to engage in active and frequent trading and expects to have a high portfolio turnover rate (over 100%). This may increase the Fund's brokerage commission costs, which would reduce performance. Rapid portfolio turnover also exposes shareholders to a higher current realization of short-term gains which could cause you to pay higher taxes.

Counterparty Risk: The Fund may enter into various types of derivative contracts with a counterparty that may be privately negotiated in the over-the-counter market. These contracts involve exposure to credit risk because contract performance depends, in part, on the financial condition of the counterparty. If a privately negotiated over-the-counter contract calls for payments by the Fund, the Fund must be prepared to make such payments when due. In addition, if the creditworthiness of the counterparty declines, the Fund may not receive payments owed under the contract, or such payments may be delayed and the value of agreements with the counterparty can be expected to decline, potentially resulting in losses to the Fund.

Temporary Investment/Cash Management Risk: The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

Swap Risk: The Fund may enter into total return swaps to gain investment exposure to the underlying security or securities in a more efficient or economically attractive manner than direct ownership. In a standard "swap" transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments. The Fund may also enter into credit default or credit default index swaps with qualified broker-dealer counterparties. In a credit default swap, one party typically makes an upfront payment and a stream of payments to another party in exchange for the right to receive a specified return in the event of a default by a referenced entity on its obligation or other credit-related event. The Fund may use swaps for any investment purpose, including as part of a merger arbitrage or event-driven strategy involving pending corporate reorganizations. Certain categories of swap agreements often have terms of greater than seven days and may be considered illiquid. Moreover, the Fund bears the risk of loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. The swaps market is subject to extensive regulation under the Dodd-Frank Act and certain Securities and Exchange Commission and Commodity Futures Trading Commission rules promulgated thereunder. It is possible that developments in the swaps market, including new and additional government regulation, could result in higher Fund costs and expenses and could adversely affect the Fund's ability, among other things, to terminate existing swap agreements or to realize amounts to be received under such agreements.

Options Risk: Options transactions involve special risks that may make it difficult or impossible to close a position when the Fund desires. These risks include possible imperfect correlation between the price movements of the option and the underlying security; the potential lack of a liquid secondary

WATER ISLAND CREDIT OPPORTUNITIES FUND

market at any particular time; and possible price fluctuation limits. In addition, the option activities of the Fund may affect its portfolio turnover rate and the amount of brokerage commissions paid by the Fund.

Preferred Securities Risk: Investments in preferred stocks may be subject to the risks of deferred distribution payments, subordination to debt instruments, a lack of liquidity compared to equities, limited voting rights, and sensitivity to interest-rate changes.

Investment Company and ETF Risk: Investing in securities issued by other investment companies, including ETFs, involves risks similar to those of investing directly in the securities and other assets held by the investment company or ETF. The Fund will indirectly bear its pro rata share of the fees and expenses incurred by a fund it invests in, including advisory fees. These expenses are in addition to the advisory and other expenses that the Fund bears directly in connection with its own operations. Unlike shares of typical mutual funds, shares of ETFs are traded on an exchange through a trading day and bought and sold based on market values and not at net asset value. For this reason, shares could trade either at a premium or a discount to net asset value. The trading price of an ETF is expected to closely track the actual net asset value of an ETF, and the Fund will generally gain or lose value consistent with the performance of the ETF's portfolio securities. The Fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs. An index-based ETF may not replicate exactly the performance of the benchmark index it seeks to track for a number of reasons, including transaction costs incurred by the ETF, the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting of securities or the number of securities held.

Derivatives Risk: In general, a derivative instrument typically involves leverage and provides exposure to potential gain or loss from a change in the market price of the underlying asset (or a basket of assets or an index) in a notional amount that exceeds the amount of cash or assets required to establish or maintain the derivative instrument. Adverse changes in the value or price of the underlying asset (or basket of assets or index), which the Fund may not directly own, can result in a loss to the Fund substantially greater than the amount invested in the derivative itself. The use of derivative instruments also exposes the Fund to additional risks and transaction costs. Derivative instruments come in many varieties and may include forward contracts, options (both written and purchased), and swap contracts.

Currency Risk: Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency denominated investments and may widen any losses. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. The return of currency forward and futures contracts utilized for currency hedging may not perfectly offset the actual fluctuations of the foreign currencies relative to the U.S. dollar and may prevent the Fund from realizing gains from an increase in the value of the currency. In addition to currency risk, currency forward/futures contracts, like other derivatives, may be susceptible to credit risk and other risks.

Foreign Securities Risk: The securities of foreign issuers may be less liquid and more volatile than securities of comparable U.S. issuers. The costs associated with securities transactions may be higher in foreign countries than in the U.S. The U.S. dollar value of foreign securities traded in foreign currencies held by the Fund or by funds in which the Fund invests (and any dividends and interest earned) may be affected favorably or unfavorably by changes in foreign currency exchange rates. An increase in the U.S. dollar relative to these other currencies may adversely affect the Fund. Additionally, investments in foreign securities, even those publicly traded in the U.S., may involve risks which are in addition to those inherent in U.S. investments. Foreign companies may not be subject to the same regulatory requirements of U.S. companies, and as a consequence, there may be less publicly available information about such companies. Also, foreign companies may not be subject to uniform accounting, auditing, and financial reporting standards and requirements comparable to those applicable to U.S. companies. Foreign governments and foreign economies often are less stable than the U.S. Government and the U.S. economy.

Performance Information

The following information provides some indication of the risks and variability of investing in the Fund by showing how the Fund's performance has varied from year to year and by showing how the Fund's average annual returns for the past one- and five-year and since inception periods compare with those of the Bloomberg U.S. Aggregate Bond Index and the ICE BofA U.S. 3-Month Treasury Bill Index.

The bar chart presents the calendar year total returns of the Fund's Class R Shares before taxes. Returns shown in the bar chart do not reflect sales charges applicable to other share classes, which would reduce performance results. The performance table reflects the performance of the Fund's Class R shares before and after taxes and the Fund's Class I and Class A shares before taxes. How the Fund has performed in the past (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Performance reflects fee waivers in effect. If fee waivers were not in place, the Fund's performance would be reduced. Updated information on the Fund's performance can be obtained by visiting www.arbitragefunds.com.

Average Annual Total Returns for Periods Ended December 31, 2024

The table below shows the Fund's average annual total returns for Class R shares, Class I shares, and Class A shares compared with those of the Bloomberg U.S. Aggregate Bond Index and the ICE BofA U.S. 3-Month Treasury Bill Index. The returns in the table below reflect the maximum applicable sales charges for the relevant share class. The table also presents the impact of taxes on the returns of the Fund's Class R shares. After-tax returns are shown for Class R shares only, and after-tax returns for Class I and Class A shares will vary. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return after taxes on distributions measures the effect of taxable distributions, but assumes the underlying shares are held for the entire period. Return after taxes on distributions and sale of Fund shares shows the effect of both taxable distributions and any taxable gain or loss that would be realized if the underlying shares were purchased at the beginning and sold at the end of the period (for purposes of the calculation, it is assumed that income dividends and capital gain distributions are reinvested at net asset value and that the entire account is redeemed at the end of the period, including reinvested amounts).

Average Annual Total Returns

* The inception date for Class R shares and Class I shares is October 1, 2012. The inception date for the Class A shares is June 1, 2013. The "Since Inception" returns reflected for the Bloomberg U.S. Aggregate Bond Index and the ICE BofA U.S. 3-Month Treasury Bill Index are based on the inception date for Class R and Class I shares.

** Due to new regulatory requirements, effective May 31, 2024, the Bloomberg U.S. Aggregate Bond Index became the Fund's broad-based securities market index. The Bloomberg U.S. Aggregate Bond Index serves as the Fund's regulatory index and provides a broad measure of market performance. The Bloomberg U.S. Aggregate Bond Index is a market value-weighted index of investment grade fixed-rated debt issues, including government, corporate, asset-backed and mortgage-backed securities with a maturity of one year or more.

*** The ICE BofA U.S. 3-Month Treasury Bill Index is the Fund's additional index. The ICE BofA U.S. 3-Month Treasury Bill Index tracks the performance of the U.S. Treasury Bills publicly issued in the U.S. domestic market with a remaining term to final maturity of less than 3 months.

The indexes are calculated on a total-return basis, are unmanaged and are not available for direct investment. The indexes reflect no deduction for fees, expenses, or taxes. The indexes are not intended to, and do not, parallel the risk or investment style of the Fund's investment strategy.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Return After Taxes on Distributions and Sale of Fund Shares to be greater than the Return After Taxes on Distributions or even the Return Before Taxes.

WATER ISLAND CREDIT OPPORTUNITIES FUND

Investment Adviser

Water Island Capital, LLC is the investment adviser ("Adviser") of the Fund.

The Fund is team-managed, with multiple named portfolio managers working in cooperation with the additional members of the Adviser's investment team to make investment decisions for the Fund. While named portfolio managers are jointly and primarily responsible for the day-to-day management of the Fund, the Fund has also designated a lead portfolio manager who is ultimately responsible for managing the Fund in accordance with its investment objective(s) and strategies.

Portfolio Managers

Purchase and Sale of Fund Shares

Minimum Investment Amounts Class R Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

Minimum Investment Amounts Class I Shares - The minimum initial investment for all types of accounts is $100,000. There is no minimum for subsequent investments other than investments through the Fund's Automatic Investment Plan, which has a $100 minimum for investments.

You may conduct transactions by mail (Regular Mail to The Arbitrage Funds, c/o SS&C GIDS, P.O. Box 219842, Kansas City, Missouri 64121-9842, or Express/Overnight Mail to The Arbitrage Funds, c/o SS&C GIDS, 801 Pennsylvania Avenue, Suite 219842, Kansas City, Missouri 64105-1307), or by telephone at (800) 295-4485. Transactions will only occur on days the New York Stock Exchange ("NYSE") is open. Investors who wish to purchase, exchange, or redeem Class R or Class I shares through a broker-dealer should contact the broker-dealer regarding the hours during which orders to purchase, exchange, or sell shares of the Fund may be placed. The Fund's transfer agent is open from 9:00 a.m. to 5:00 p.m. Eastern Time for purchase, exchange, or redemption orders.

Minimum Investment Amounts Class A Shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments in Class A shares.

Purchases, exchanges, and redemptions of Class A shares can be made only through institutional channels, such as financial intermediaries and retirement platforms, which have established an agreement with the Fund's distributor. Financial intermediaries may charge additional fees for their services, including ticket and/or transaction fees for processing trades. You should contact your financial intermediary or refer to your plan documents for information on how to invest in the Fund. Requests must be received in good order by the Fund or its agent (financial intermediary or plan sponsor, if applicable) prior to the close of the regular trading session of the NYSE in order to receive that day's net asset value.

Tax Information

The Fund's distributions are generally taxable as ordinary income or capital gains, unless you are investing through a tax-exempt or tax-deferred arrangement, such as a 401(k) plan or an individual retirement account, in which case such distributions may be taxable when withdrawn from such account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

ADDITIONAL IMPORTANT INFORMATION REGARDING FUND EXPENSES AND DIVIDENDS ON SHORT POSITIONS

When a Fund sells a security short, the Fund borrows the security from a lender and then sells the security in the general market. A Fund is obligated to pay any interest accrued or dividend declared during the period in which the Fund maintains the short position to the lender from which the Fund borrowed the security, and the Fund is obligated to record the payment of the accrued interest or dividend as an expense. Dividend expenses are not fees directly charged to shareholders by a Fund or any Fund service provider but are similar to finance charges incurred by the Fund in borrowing transactions. Dividends, whether earned by a Fund on long positions, or paid by a Fund on short positions, are taken into account by the Adviser when calculating the return potential of its investments.

Arbitrage Fund

Excluding the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings, Arbitrage Fund's total annual operating expenses (expenses that are deducted from Fund assets) are as set forth below. Please refer to the table in the Fund's "Fees and Expenses" discussion on page 2 for details on the Fund's Total Annual Operating Expenses including the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings; and see the accompanying footnote for details relating to the Acquired Fund Fees and Expenses.

Water Island Event-Driven Fund

Excluding the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings, Water Island Event-Driven Fund's total annual operating expenses (expenses that are deducted from Fund assets) are as set forth below. Please refer to the table in the Fund's "Fees and Expenses" discussion on page 10 for details on the Fund's Total Annual Operating Expenses including the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings, and see the accompanying footnotes for details relating to the Acquired Fund Fees and Expenses and the Amended and Restated Expense Waiver and Reimbursement Agreement.

Arbitrage Fund
Water Island Event-Driven Fund
Water Island Credit Opportunities Fund

Water Island Credit Opportunities Fund

Excluding the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings, Water Island Credit Opportunities Fund's total annual operating expenses (expenses that are deducted from Fund assets) are as set forth below. Please refer to the table in the Fund's "Fees and Expenses" discussion on page 19 for details on the Fund's Total Annual Operating Expenses including the effect of expenses attributable to dividends on short positions and interest on short positions and/or borrowings, and see the accompanying footnotes for details relating to the Acquired Fund Fees and Expenses and the Amended and Restated Expense Waiver and Reimbursement Agreement.

THE ARBITRAGE FUNDS

INVESTMENT OBJECTIVE, POLICIES, AND RISKS

Investment Objective

Arbitrage Fund seeks to achieve capital growth by engaging in merger arbitrage.

Water Island Event-Driven Fund seeks to achieve capital growth.

Water Island Credit Opportunities Fund seeks to provide current income and capital growth.

Each of the Funds may change its investment objective without shareholder approval.

Principal Investment Strategies and Policies

Arbitrage Fund

To achieve its investment objective, Arbitrage Fund, under normal market conditions, will invest at least 80% of its net assets (including borrowings for investment purposes) in equity securities of companies (both U.S. and foreign) involved in publicly announced mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other types of corporate reorganizations (all referred to as "corporate reorganizations"). Equity securities include common and preferred stock. The Fund may invest in equity securities of companies of any market capitalization.

Merger arbitrage refers to the investment practice of capturing the difference between the end value of a corporate reorganization and the prevailing market prices of the securities of the companies involved prior to the consummation of the reorganization. It is a highly specialized investment approach designed to profit from the successful completion of such reorganizations. The discrepancy in value is attributable to risks that are inherent in corporate reorganizations, which include the possibility the transaction will not be completed and the time it takes for corporate reorganizations to be completed.

The Fund continuously monitors not only the investment positions owned by the Fund, but also other potential mergers and corporate reorganizations. This enables the Fund to make timely and informed investment decisions if market prices of other securities adjust enough so that it becomes attractive for the Fund to make new investments for its own portfolio. The Adviser expects the Fund's assets to be invested across various industries; however, if for example, a large percentage (namely, at least 50%) of mergers or other corporate events taking place within the U.S. are within one industry over a given period of time, a large portion of the Fund's assets could be concentrated in that industry for that period of time.

The most common merger arbitrage activity, and the approach the Fund primarily uses, involves purchasing the shares of an announced acquisition target at a discount to their expected value upon completion of the acquisition. The Adviser will carefully evaluate all potential arbitrage investment opportunities examining each situation's return characteristics together with its risk profile. As an important part of this investment process, the Fund systematically reduces market exposure by employing various hedging strategies, as discussed below.

The Fund generally engages in active and frequent trading of portfolio securities to achieve its principal investment strategies. Active and frequent trading of portfolio securities could produce higher trading and transaction costs and larger taxable distributions. When determining whether to sell or close out a security, the Adviser continuously reviews and rationalizes each investment's risk versus its reward relative to its predetermined exit strategy. The Fund will generally sell or close out a security when the securities of the companies involved in the transaction do not meet the Fund's expected return criteria when gauged by prevailing market prices and the relative risks of the situation.

The principal hedging strategies that the Fund employs are short selling and the use of put and call options. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. Furthermore, the Fund may invest in other investment companies, including funds advised by the Adviser, and in exchange traded funds ("ETFs"). The Fund limits its investments in other investment companies (excluding money market funds) to no more than 10% of its total assets.

Short Sales: The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the common stock of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities as per the terms of the transaction may be sold short. Occasionally, the common stock of the acquiring company may be purchased and the common stock of the company to be acquired may be sold short. The Fund will make these short sales with the intention of later closing out (or covering) the short position with the securities of the acquiring company received when the acquisition is consummated. The purpose of the short sale is to protect against a decline in the market value of the acquiring company's securities prior to the acquisition's completion. At all times when the Fund does not own securities which are sold short, the Fund will maintain collateral consisting of cash, cash equivalents, and liquid securities equal in value on a daily marked-to-market basis to the securities sold short.

Put and Call Options: The Fund may engage in purchasing and/or selling put and call options in an effort to reduce the risks associated with some of its investments. A put option is a short-term contract which gives the purchaser of the option, in return for a premium paid, the right to sell the underlying security at a specified price upon exercise of the option at any time prior to the expiration of the option. The market price of a put option normally will vary inversely with the market price of the underlying security. Consequently, by purchasing put options on securities the Fund has purchased, it may be possible for the Fund to partially offset any decline in the market value of these securities. A call option, on the other hand, is a short-term contract

entitling the purchaser, in return for a premium paid, the right to buy the underlying security at a specified price upon exercise of the option, at any time prior to its expiration. The market price of the call, in most instances, will move in conjunction with the price of the underlying security.

The premium received by the Fund for the sale of options may be used by the Fund to reduce the risks associated with individual investments and to increase total investment return. Currently, the Adviser does not intend to commit greater than 25% of the Fund's net assets to option strategies.

The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political, or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

Water Island Event-Driven Fund

To achieve its investment objective, Water Island Event-Driven Fund invests in equity and debt and debt-like securities of companies that are impacted by corporate events such as mergers, acquisitions, asset sales, restructurings, refinancings, recapitalizations, reorganizations, or other special situations. In order to achieve its investment objective, the Fund may employ investment strategies such as merger arbitrage, convertible arbitrage, capital structure arbitrage, and special situations in order to profit from event-driven opportunities. The Fund may invest in both U.S. and foreign securities and may invest in securities of companies of any market capitalization and in debt securities of any maturity and credit quality. The Fund may also invest in derivatives, such as options and swaps. Furthermore, the Fund may invest in ETFs. The Fund limits its investments in other investment companies (excluding money market funds) to no more than 10% of its total assets.

Merger Arbitrage: Merger arbitrage is a highly specialized investment approach designed to profit from the successful completion of mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. The most common merger arbitrage activity, and the approach the Fund generally uses, involves purchasing the shares of an announced acquisition target company at a discount to their expected value upon completion of the acquisition. The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the securities of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities as per the terms of the transaction may be sold short. Occasionally, the common stock of the acquiring company may be purchased and the common stock of the company to be acquired may be sold short.

Convertible Arbitrage: Convertible arbitrage is a specialized strategy that seeks to profit from pricing inefficiencies between a firm's convertible securities and its underlying equity. The most common convertible arbitrage approach, and the strategy the Fund generally uses when it believes that the common stock is overvalued in relation to the convertible securities, matches a long position in the convertible security with a short position in the underlying common stock. The Fund seeks to purchase convertible securities at discounts to their expected future values and sell short shares of the underlying common stock in order to mitigate equity market movements. As stock prices rise and the convertible security becomes more equity sensitive, the Fund will sell short additional common shares in order to maintain the relationship between the convertible and the underlying common stock. As stock prices fall, the Fund will typically buy back a portion of shares which it had sold short. Positions are typically designed to earn income from coupon or dividend payments, and from the short sale of common stock.

Capital Structure Arbitrage: Capital structure arbitrage seeks to profit from relative pricing discrepancies between related debt and/or equity securities. For example, when the Fund believes that unsecured securities are overvalued in relation to senior secured securities, the Fund may purchase a senior secured security of an issuer and sell short an unsecured security of the same issuer. In this example the trade would be profitable if credit quality spreads widened or if the issuer went bankrupt and the recovery rate for the senior debt was higher than anticipated. Another example might involve the Fund purchasing one class of common stock while selling short a different class of common stock of the same issuer. It is expected that, over time, the relative mispricing of the securities may decline, at which point the position will be liquidated.

Special Situations: The special situations strategy seeks to profit by investing in securities of companies whose stock price trades significantly higher or lower from where the Adviser believes they should trade, as the result of an ongoing or anticipated corporate catalyst. Corporate catalysts may include spin-offs, split-offs, asset sales, speculative mergers and acquisitions, transformational mergers and acquisitions, Dutch tenders (whereby an offer is made to purchase securities within a given price range through an auction structure, wherein shareholders are invited to sell shares over a specific time period by specifying the lowest price within the range that they will accept), regulatory changes, recapitalizations, refinancings, corporate levering/de-levering, un-solicited hostile offers, litigation, bankruptcy processes, distressed credit, and other catalysts. The strategy invests primarily in equity securities, but may also invest in debt, warrants, debentures, convertible securities, and preferred securities. The strategy may engage in short sales and derivatives to implement trading strategies and to mitigate volatility and market risk.

The Fund continuously monitors its investments and evaluates each investment's risk/return profile, not only for each investment by itself, but also in the context of the Fund's overall portfolio and the availability of other event-driven opportunities. As a result of this continuous examination of investment

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conditions, the Fund will not necessarily use each of its available strategies (principal and non-principal) at a particular time, but rather will allocate its investments according to what the Adviser believes are the best risk-adjusted event-driven opportunities available.

The Adviser expects the Fund's assets to be invested in various industries; however, if, for example, a large percentage (namely, at least 50%) of corporate events taking place within the U.S. are within one industry over a given period of time, a large portion of the Fund's assets could be concentrated in that industry for that period of time.

The principal hedging strategies that the Fund employs are short selling and the use of put and call options.

The Fund normally expects to engage in active and frequent trading of portfolio securities to achieve its investment objective. Active and frequent trading of portfolio securities could produce higher trading and transaction costs and larger taxable distributions. When determining whether to sell or close out a security, the Adviser continuously reviews and rationalizes each investment's risk versus its reward relative to its predetermined exit strategy. The Fund will sell or close out a security when the securities of the companies involved in the transaction do not meet the Fund's expected return criteria when gauged by prevailing market prices and the relative risks of the situation. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies.

The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political, or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

The Fund is non-diversified, which means that it may invest a greater portion of its assets in one or a limited number of issuers and may invest overall in a smaller number of issuers than a diversified fund.

Water Island Credit Opportunities Fund

Water Island Credit Opportunities Fund invests primarily in a portfolio of debt and debt-like instruments including corporate bonds and debentures (including high yield bonds commonly known as "junk bonds"), bank loans, convertible and preferred securities, credit default swaps and other debt instruments and derivatives that the Adviser believes have debt-like characteristics. The Fund invests in both U.S. and foreign debt securities. The principal types of derivatives in which the Fund may invest are credit default swaps, interest rate swaps, swaps, futures, and options.

The Fund invests primarily in debt securities whose returns the Adviser believes will be more correlated with the outcome of specific catalysts or events rather than overall market direction. These catalysts and events include mergers, acquisitions, debt maturities, refinancings, regulatory changes, recapitalizations, reorganizations, restructurings, and other special situations. The Fund also uses a relative value approach and may express positive views on specific credits by taking long positions in cash bonds and/or derivatives and negative views on specific credits by taking short positions in cash bonds and/or derivatives. The Fund uses fundamental research to identify mispricings or inefficiencies in these situations and assess their potential impact on security prices.

The Fund may engage in short-term trading strategies and may engage in short sales and invest in derivatives. The principal short-term trading strategies may at times include convertible arbitrage, merger arbitrage, and capital structure arbitrage, which are discussed below. The Fund may seek to mitigate the risk of volatility (the appreciation and depreciation of the value of a security over a period of time) and duration (the impact of interest rate changes on fixed-income securities) by engaging in short sales and/or investing in derivatives, including credit default swaps, interest rate swaps, futures, and options. The Fund may purchase or sell short equity securities or derivatives as part of a hedging strategy or hold equity positions or other assets that the Fund receives as part of a reorganization process. The Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. Furthermore, the Fund may invest in ETFs.

The principal hedging strategies that the Fund employs are short selling and the use of put and call options.

The Fund is not limited with respect to its portfolio maturity or duration. The Fund may invest in debt securities without regard to their credit ratings, including unrated securities, securities that are non-investment grade, and in debt securities with a wide variety of terms that may vary from security to security, including but not limited to optional and mandatory prepayment provisions, fixed, variable, semi-variable, and resettable interest rates and conversion options, as well as various combinations of these terms.

Convertible Arbitrage: Convertible arbitrage is a specialized strategy that seeks to profit from pricing inefficiencies between a firm's convertible securities and its underlying equity. The most common convertible arbitrage approach, and the strategy the Fund generally uses, when it believes that the common stock is overvalued in relation to the convertible securities, matches a long position in the debt securities, preferred stocks, and other securities convertible into common stock with a short position in the underlying common stock. The Fund seeks to purchase such convertible securities at discounts to their expected future values and sell short shares of the underlying common stock in order to mitigate equity market movements. As stock prices rise and the convertible security becomes more equity sensitive, the Fund may sell short additional common shares in order to maintain the

relationship between the convertible and the underlying common stock. As stock prices fall, the Fund will typically buy back a portion of shares which it had sold short. Positions are typically designed to earn income from coupon or dividend payments, and from the short sale of common stock.

Merger Arbitrage: Merger arbitrage is a highly specialized investment approach designed to profit from the successful completion of mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations, and other corporate reorganizations. The most common merger arbitrage activity, and the approach the Fund generally uses, involves purchasing the shares of an announced acquisition target company at a discount to their expected value upon completion of the acquisition. The Fund may engage in selling securities short when the terms of a proposed acquisition call for the exchange of common stock and/or other securities. In such a case, the securities of the company to be acquired may be purchased and, at approximately the same time, an amount of the acquiring company's common stock and/or other securities as per the terms of the transaction may be sold short.

Capital Structure Arbitrage: Capital structure arbitrage seeks to profit from relative pricing discrepancies between related debt and/or equity securities. For example, when the Fund believes that unsecured securities are overvalued in relation to senior secured securities, the Fund may purchase a senior secured security of an issuer and sell short an unsecured security of the same issuer. In this example the trade would be profitable if credit quality spreads widened or if the issuer went bankrupt and the recovery rate for the senior debt was higher than anticipated. It is expected that, over time, the relative mispricing of the securities may decline, at which point the position will be liquidated.

The Fund may also employ a hedging program that will focus on reducing the impact of market risk, interest rate risk, credit risk, and idiosyncratic events. This hedging program is intended to reduce the portfolio's overall volatility. This program may include the purchase and sale of instruments such as equities and derivatives, including options and swaps.

The Fund continuously monitors its investments and evaluates each investment's risk/return profile, not only for each investment by itself, but also in the context of the Fund's overall portfolio and the availability of other event-driven opportunities. As a result of this continuous examination of investment conditions, the Fund will not necessarily use each of its available strategies (principal and non-principal) at a particular time, but rather will allocate its investments according to what the Adviser believes are the best risk-adjusted opportunities available.

The Fund normally expects to engage in active trading of portfolio securities to achieve its principal investment objective. Active and frequent trading of portfolio securities could produce higher trading and transaction costs and larger taxable distributions. The Fund will sell or close out a security when the securities of the companies involved in the transaction do not meet the Fund's expected return criteria when gauged by prevailing market prices and the relative risks of the situation

The Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political, or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent the Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

Principal Investment Risks

All investments, including those in mutual funds entail risks that could cause a Fund and you to lose money. The SUMMARY SECTION for each of the Funds discusses the principal risks applicable to that Fund. The risks identified in the table below are the principal risks and certain non-principal risks of investing in each Fund. Unlike the risks in the SUMMARY SECTION, the risks below are presented in alphabetical order and not in order of importance.

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Active Management Risk: Each Fund is an actively managed investment portfolio and is therefore subject to management risk. The Adviser will apply its investment and risk analysis in making investment decisions for the Fund, but there is no guarantee that these decisions will produce the intended results.

Artificial Intelligence Risk: Each Fund and its service providers, including the Adviser, may utilize artificial intelligence ("AI") technologies, including machine learning models and generative AI, to improve operational efficiency and in connection with research. In addition, counterparties used by the Funds may utilize AI in their business activities. While the Adviser may restrict certain uses of AI tools, the Funds and the Adviser are not in a position to control the use of AI in third-party products or services. The use of AI introduces numerous potential challenges and the use of AI can lead to reputational damage, legal liabilities, and competitive disadvantages, as well as negatively impact business operations, which may occur with or without mismanagement in the use of the AI. AI requires the collection and processing of substantial amounts of data, which poses risks of data inaccuracies, incompleteness, and inherent biases, and which can degrade the technology's effectiveness and reliability. The complexity of AI systems raise significant accountability and ethical concerns. AI has enhanced the ability of threat actors to amplify the potency, scale, and speed of cybersecurity attacks. AI's role in increasing automation raises concerns about job displacement and may lead to economic and social disruptions. The unpredictable nature of AI's impact on market dynamics complicates traditional risk assessment models, making it challenging to identify risks and opportunities using historical data. Legal and regulatory frameworks governing AI's use, particularly concerning data privacy and protection, are evolving rapidly. These changes could materially alter how AI is used, which may negatively impact the Funds.

Concentration Risk: Each Fund (except Water Island Credit Opportunities Fund) may, if a large percentage of mergers, corporate events or event-driven investment opportunities taking place within the U.S. are within one industry over a given period of time, invest a large portion of its assets in securities of issuers in a single industry for that period of time. During such a period of concentration, the Fund may be subject to greater volatility with respect to its portfolio securities than a fund that is more broadly diversified.

Convertible Security Risk: Convertible securities generally offer lower interest or dividend yields than non-convertible securities of similar quality. Because convertible securities are higher in the firm's capital structure than equity, convertible securities are generally not as risky as the equity securities of the same issuer. However, convertible securities may gain or lose value due to changes in interest rates and other general economic conditions, industry fundamentals, market sentiment, and changes in the issuer's operating results and credit ratings.

Counterparty Risk: The Funds may enter into various types of derivative contracts with a counterparty that may be privately negotiated in the over-the-counter market. These contracts involve exposure to credit risk because contract performance depends, in part, on the financial condition of the counterparty. If a privately negotiated over-the-counter contract calls for payments by a Fund, the Fund must be prepared to make such payments when due. In addition, if the creditworthiness of the counterparty declines, the Fund may not receive payments owed under the contract, or such payments may be delayed under such circumstances and the value of agreements with such counterparty can be expected to decline, potentially resulting in losses to the Fund.

Credit Risk: Credit risk refers to the possibility that the issuer of the security will not be able to make interest or principal payments when due. A Fund may invest in convertible and non-convertible debt securities, including high yield debt securities, also known as "junk bonds." Investments in junk bonds are subject to greater credit risks than securities with credit ratings above investment grade and have a greater risk of default than investment grade debt securities. Junk bonds are less sensitive to interest rate changes than higher credit quality instruments and generally are more sensitive to adverse economic changes or individual corporate developments.

Currency Risk: Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign currency denominated investments and may widen any losses. Each Fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies. The return of the forward currency contracts and currency futures contracts utilized for currency hedging may not perfectly offset the actual fluctuations of the foreign currencies relative to the U.S. dollar and may prevent a Fund from realizing gains from an increase in the value of the currency. In addition to currency risk, currency forward/futures contracts, like other derivatives, may be susceptible to credit risk and other risks.

Derivatives Risk: In general, a derivative instrument typically involves leverage and provides exposure to potential gain or loss from a change in the market price of the underlying asset (or a basket of assets or an index) in a notional amount that exceeds the amount of cash or assets required to establish or maintain the derivative instrument. Adverse changes in the value or level of the underlying asset (or basket of assets or index), which a Fund may not directly own, can result in a loss to the Fund substantially greater than the amount invested in the derivative itself. The use of derivative instruments also exposes a Fund to additional risks and transaction costs. These instruments come in many varieties and may include forward contracts, options (both written and purchased), and swap contracts.

Derivatives may not behave as anticipated by a Fund, and derivatives strategies that are successful under certain market conditions may be less successful or unsuccessful under other market conditions. A Fund also may be exposed to losses if the counterparty in the transaction is unable or unwilling to fulfill its contractual obligation. In certain cases, a Fund may be delayed in exercising remedies against or closing out derivatives with a counterparty, resulting in additional losses. Derivatives also may be subject to the risk of mispricing or improper valuation, and valuation may be more difficult in times of market turmoil. Changes to the regulation of derivatives markets and mutual funds' use of derivatives may impact a Fund's ability to maintain its investments in derivatives, make derivatives more costly, limit their availability, adversely affect their value or performance, or otherwise disrupt markets.

Event-Driven Risk: Event-driven investments involve the risk that certain of the events driving the investment may not happen or the market may react differently than expected to the anticipated transaction. In addition, although an event may occur or is announced, it may be renegotiated, terminated, or involve a longer time frame than originally contemplated. Event-driven investment transactions are also subject to the risk of overall market movements. Any one of these risks could cause a Fund to experience investment losses impacting its shares negatively.

Foreign Securities Risk: The securities of foreign issuers may be less liquid and more volatile than securities of comparable U.S. issuers. The costs associated with securities transactions may be higher in foreign countries than in the U.S. The U.S. dollar value of foreign securities traded in foreign currencies held by a Fund or by funds in which a Fund invests (and any dividends and interest earned) may be affected favorably or unfavorably by changes in foreign currency exchange rates. An increase in the U.S. dollar relative to these other currencies may adversely affect a Fund. Additionally, investments in foreign securities, even those publicly traded in the U.S., may involve risks which are in addition to those inherent in U.S. investments. Foreign companies may not be subject to the same regulatory requirements of U.S. companies, and as a consequence, there may be less publicly available information about such companies. Also, foreign companies may not be subject to uniform accounting, auditing, and financial reporting standards and requirements comparable to those applicable to U.S. companies. Foreign governments and foreign economies often are less stable than the U.S. Government and the U.S. economy. In addition, certain investments in non-U.S. securities may be subject to foreign withholding and other taxes on interest, dividends, capital gains or other income or proceeds. Those taxes will reduce the Fund's yield on any such securities.

Hedging Transaction Risk: The success of a Fund's hedging strategies will be subject to the Adviser's ability to assess correctly the degree of correlation between the performance of the instruments used in the hedging strategies and the performance of the investments in the Fund's portfolio being hedged. Hedging transactions involve the risk of imperfect correlation. Imperfect correlation may prevent a Fund from achieving the intended hedge or expose the Fund to risk of loss. Hedging transactions also limit the opportunity for gain if the value of a hedged portfolio position should increase.

High Portfolio Turnover Risk: The Funds normally expect to engage in active and frequent trading and expect to have high portfolio turnover rates (over 100%). This may increase a Fund's brokerage commission costs, which would reduce performance. Rapid portfolio turnover also exposes shareholders to a higher current realization of short-term gains which could cause you to pay higher taxes.

Interest Rate Risk: Prices of debt securities and preferred stocks tend to move inversely with changes in interest rates. When interest rates fall, the market value of the respective debt securities and preferred securities usually increases. Conversely, when interest rates rise, the market value of the respective debt securities and preferred securities usually declines. As such, a change in interest rates may affect prices of a Fund's debt securities and preferred securities and, accordingly, the Fund's share price.

Investment Company and ETF Risk: Investing in securities issued by other investment companies, including ETFs, involves risks similar to those of investing directly in the securities and other assets held by the investment company or ETF. Each Fund will indirectly bear its pro rata share of the fees and expenses incurred by a fund it invests in, including advisory fees. These expenses are in addition to the advisory and other expenses that a Fund bears directly in connection with its own operations. Unlike shares of typical mutual funds, shares of ETFs are traded on an exchange through a trading day and bought and sold based on market values and not at net asset value. For this reason, shares could trade either at a premium or a discount to net asset value. The trading price of an ETF is expected to closely track the actual net asset value of an ETF, and a Fund will generally gain or lose value consistent with the performance of the ETF's portfolio securities. A Fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs. An index-based ETF may not replicate exactly the performance of the benchmark index it seeks to track for a number of

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reasons, including transaction costs incurred by the ETF, the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting of securities or the number of securities held.

Large Shareholder Transaction Risk: A significant percentage of a Fund's shares may be owned or controlled by certain large shareholders. A Fund may experience adverse effects when certain large shareholders purchase or redeem large amounts of shares of the Fund. Such large shareholder redemptions may cause a Fund to sell its securities at times when it would not otherwise do so, which may negatively impact the Fund's NAV and liquidity. In addition, a large redemption could result in a Fund's current expenses being allocated over a smaller asset base, leading to an increase in the Fund's expense ratio. Similarly, large share purchases may adversely affect a Fund's performance to the extent that the Fund is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would.

Leverage Risk: If a Fund uses leverage through activities such as borrowing, entering into short sales, purchasing securities on margin or on a "when-issued" basis or purchasing derivative instruments in an effort to increase its returns, the Fund has the risk of magnified capital losses that occur when losses affect an asset base, enlarged by borrowings or the creation of liabilities, that exceeds the net assets of the Fund. Should a Fund employ leverage, the Fund's net asset value may be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest. If the interest expense on borrowings were to exceed the net return on the portfolio securities purchased with borrowed funds, the Fund's use of leverage would result in a lower rate of return than if the Fund was not leveraged.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell. Liquidity risk may be the result of, among other things market turmoil, the reduced number and capacity of traditional market participants to make a market in fixed-income securities, or the lack of an active market. Markets for securities or financial instruments could be disrupted by a number of events, including, but not limited to, an economic crisis, natural disasters, new legislation, or regulatory changes inside or outside the U.S. Liquid investments may become less liquid after being purchased by a Fund, particularly during periods of market stress. To enhance investment value and/or protect shareholder rights, from time to time, a Fund may participate in various types of litigation, including but not limited to shareholder appraisal rights petitions and class action lawsuits. A Fund exercising appraisal rights may experience limited liquidity on its investment while the subject securities are being appraised. Illiquid and relatively less liquid investments may be harder to value, especially in turbulent markets and if a Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss.

Market Disruption Risks Related to Armed Conflict: As a result of increasingly interconnected global economies and financial markets, armed conflict between countries or in a geographic region has the potential to adversely impact a Fund's investments. Such conflicts, and other corresponding events, have had, and could continue to have, severe negative effects on regional and global economic and financial markets, including increased volatility, reduced liquidity, and overall uncertainty. The negative impacts may be particularly acute in certain sectors. The timing and duration of such conflicts, resulting sanctions, related events and other impacts cannot be predicted. The foregoing may result in a negative impact on Fund performance and the value of an investment in a Fund, even beyond any direct investment exposure a Fund may have to issuers located in or with significant exposure to an impacted country or geographic regions.

Market Risk: Market risk is the possibility that securities prices will fluctuate over time, sometimes rapidly and unpredictably. This fluctuation includes both increases and decreases in security prices. Each Fund is subject to market risk. The value of a Fund's investments, and the net asset value of the Fund, will fluctuate. Investors could lose money due to this price fluctuation. Securities markets may experience long periods of decline in value. The value of a security may decline due to factors that are specifically related to a particular company, as well as general market conditions, such as real or perceived adverse economic or political conditions, inflation rates or investor expectations concerning such rates, changes in interest rates, recessions, or adverse investor sentiment generally. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Changes in the financial condition of a single issuer can impact a market as a whole. Local, regional, or global events such as war, acts of terrorism, sanctions, the spread of infectious illness or other public health issues, natural disasters, or other developments could also have a significant adverse impact on a Fund and its investments.

Policy changes by the U.S. Government or U.S. Federal Reserve and political and other events within the U.S. could cause uncertainty in the markets, may affect investor and consumer confidence, and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. Decisions by the U.S. Federal Reserve regarding interest rate and monetary policy, which can be difficult to predict and sometimes change direction suddenly in response to economic and market events, can have a significant effect on the financial system and could impact a Fund and its investments. Precise interest rate predictions are difficult to make, and interest rates may change unexpectedly and dramatically in response to extreme changes in market or economic conditions. A downgrade of the ratings of, or a default on, U.S. Government debt obligations, or concerns about the U.S. Government's credit quality in general, could have a substantial negative effect on the U.S. and global economies. High public debt in the U.S. and other countries creates ongoing systemic and market risks and policymaking uncertainty.

Uncertainty regarding such events and the corresponding governmental responses could lead to corporate events such as mergers, acquisitions, and restructurings breaking or forcing a Fund to allocate assets to other strategies. Such events can be highly disruptive to economies and markets, adversely impacting individual companies, sectors, industries, markets, currencies, interest and inflation rates, credit ratings, investor sentiment, and other factors affecting the value of each Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region are increasingly likely to adversely affect markets, issuers, or foreign exchange rates in other countries. Adverse market conditions may be prolonged and may not have the same impact on all types of securities. These disruptions could prevent a Fund from executing advantageous

investment decisions in a timely manner and could negatively impact the Fund's ability to achieve its investment objective. Any such event(s) could have a significant adverse impact on the value or risk profile of a Fund.

Merger Arbitrage Risk: The principal risk associated with a Fund's merger arbitrage investment strategy is that the proposed reorganizations in which the Fund invests may not be completed or may be completed on less favorable terms and originally anticipated, including due to government regulation or intervention, in which case the Fund may realize losses. In the case of an investment in a potential target company, if the proposed transaction appears likely to not be consummated, in fact is not consummated, or is delayed, the market price of the security to be tendered or exchanged will usually decline sharply, which could result in a loss to a Fund. A transaction may be renegotiated, delayed or abandoned for a variety of reasons, and the risk/reward payout of merger arbitrage strategies typically is asymmetric, with the losses from failed transactions often exceeding the gains from successful transactions. During periods of market stress, the availability of investable transactions may be significantly limited.

Non-Diversification Risk: Water Island Event-Driven Fund is non-diversified, which means that the Fund may invest a relatively high percentage of its assets in a limited number of issuers. As a result, the Fund's performance may be more vulnerable to changes in market value of a single issuer or group of issuers and more susceptible to risks associated with the occurrence of adverse events affecting a particular issuer than a diversified fund.

Options Risk: Options transactions involve special risks that may make it difficult or impossible to close a position when a Fund desires. These risks include possible imperfect correlation between the price movements of the option and the underlying security; the potential lack of a liquid secondary market at any particular time; and possible price fluctuation limits. In addition, the option activities of a Fund may affect its portfolio turnover rate and the amount of brokerage commissions paid by a Fund.

Preferred Securities Risk: Investments in preferred stocks may be subject to the risks of deferred distribution payments, subordination to debt instruments, a lack of liquidity compared to equities, limited voting rights and sensitivity to interest-rate changes.

Sector Risk: The securities of companies in the same or related businesses ("sectors"), if comprising a significant portion of a Fund's portfolio, may in some circumstances react negatively to market conditions, interest rates and economic, regulatory or financial developments, and adversely affect the value of the Fund's portfolio, to a greater extent than if such securities comprised a lesser portion of the Fund's portfolio or the Fund's portfolio was diversified across a greater number of sectors. Some sectors have particular risks that may not affect other sectors.

Short Sale Risk: A Fund will suffer a loss if it sells a security short and the value of the security rises rather than falls. It is possible that the Fund's long positions will decline in value at the same time that the value of its short positions increase, thereby increasing potential losses to the Fund. Short sales expose a Fund to the risk that it will be required to buy the security sold short (also known as "covering" the short position) at a time when the security has appreciated in value, thus resulting in a loss to the Fund. A Fund's investment performance may also suffer if it is required to close out a short position earlier than it had intended. In addition, a Fund may be subject to expenses related to short sales that are not typically associated with investing in securities directly, such as costs of borrowing. These expenses may negatively impact a Fund's performance. When the Fund sells a security short, it must maintain cash or high-grade securities equal to the margin requirement. As a result, the Fund may maintain high levels of cash or other liquid assets (such as U.S. Treasury bills, money market instruments, certificates of deposit, high quality commercial paper and long equity positions). The need to maintain cash or other liquid assets could limit the Fund's ability to pursue other opportunities as they arise. Short positions introduce more risk to a Fund than long positions (purchases) because the maximum sustainable loss on a security purchased (held long) is limited to the amount paid for the security plus the transaction costs, whereas there is no maximum attainable price of the shorted security. Therefore, in theory, securities sold short have unlimited risk.

Small and Medium Capitalization Securities Risk: Securities issued by small and medium capitalization companies tend to be less liquid and more volatile than stocks of companies with relatively large market capitalizations. Securities of small and medium capitalization companies may be more vulnerable to adverse business or economic events than larger, more established companies. In particular, these small and medium sized companies may have limited product lines, markets and financial resources, and may depend upon a relatively small management group. Therefore, small and medium capitalization stock prices may be more volatile than those of larger companies.

Special Situations Risk: The Water Island Event-Driven Fund may seek to benefit from "special situations," such as mergers, acquisitions, consolidations, bankruptcies, liquidations, reorganizations, restructurings, tender or exchange offers, or other unusual events expected to affect a particular issuer. Investing in special situations carries the risk that certain of such situations may not happen as anticipated or the market may react differently than expected to such situations. The securities of companies involved in special situations may be more volatile than other securities, may at times be illiquid, or may be difficult to value. Certain special situations carry the additional risks inherent in difficult corporate transitions and the securities of such companies may be more likely to lose value than the securities of more stable companies.

Swap Risk: A Fund may enter into total return swaps to gain investment exposure to the underlying security or securities in a more efficient or economically attractive manner than direct ownership. In a standard "swap" transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments. Water Island Event-Driven Fund and Water Island Credit Opportunities Fund may also enter into credit default or credit default index swaps with qualified broker-dealer counterparties. In a credit default swap, one party typically makes an upfront payment and a stream of payments to another party in exchange for the right to receive a specified return in the event of a default by a referenced entity on its obligation or other credit-related event. A Fund may use swaps for any investment purpose, including as

THE ARBITRAGE FUNDS

part of a merger arbitrage or event-driven strategy involving pending corporate reorganizations. Certain categories of swap agreements often have terms of greater than seven days and may be considered illiquid. Moreover, a Fund bears the risk of loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a swap agreement counterparty. The swaps market is subject to extensive regulation under the Dodd-Frank Act and certain Securities and Exchange Commission and Commodity Futures Trading Commission rules promulgated thereunder. It is possible that developments in the swaps market, including new and additional government regulation, could result in higher Fund costs and expenses and could adversely affect a Fund's ability, among other things, to terminate existing swap agreements or to realize amounts to be received under such agreements. The value of swaps can be very volatile, and a variance in the degree of volatility or in the direction of securities prices from the Adviser's expectations may produce losses in a Fund's investments in swaps. In addition, a perfect correlation between a swap and a reference asset may be impossible to achieve. As a result, the Adviser's use of swaps may not be effective in fulfilling the Adviser's investment strategies and may contribute to losses that would not have been incurred otherwise.

Temporary Investment/Cash Management Risk: A Fund may hold a significant portion of its assets in cash, money market or similar cash management funds, or short-term investments for temporary defensive purposes in response to adverse market, economic, political, or other conditions, to preserve the Fund's ability to capitalize quickly on new market opportunities, or for other reasons, such as because the Adviser has determined to obtain investment exposure through derivative instruments instead of direct cash investments. These investments may include money market funds, money market instruments such as Treasury bills, securities issued by the U.S. Government, its agencies or instrumentalities, bankers' acceptances, commercial paper, and repurchase agreements for the above securities, and investment companies that invest primarily in such instruments. To the extent a Fund maintains cash or holds short-term investments, the Fund may not achieve its investment objective and may also be subject to additional risks, including market, interest rate, and credit risk.

Portfolio Holdings and Disclosure Policy

Each Fund's top ten portfolio holdings in order of position size are published quarterly, within the first 30 days following quarter end at https://www.arbitragefunds.com. In addition, each Fund's top five performance contributors and detractors are disclosed on the Funds' website within five to ten days of the end of each month. Additional information about a Fund's policies and procedures with respect to the disclosure of the Fund's portfolio securities, as set forth in the Funds' Portfolio Holdings and Disclosure Policy, is included in the Funds' Statement of Additional Information ("SAI").

THE ADVISER

Water Island Capital, LLC, 104 Fifth Avenue, 9th Floor, New York, New York 10011, a registered investment adviser, is the Funds' investment adviser. The Adviser was formed in 2000 and as of August 31, 2025 had approximately $1.1 billion in assets under management. Subject to the authority of the Funds' Board of Trustees, the Adviser is responsible for the overall management of each Fund's business affairs.

Arbitrage Fund pays an annual fee of 1.25% on the first $250 million of its average daily net assets, 1.20% on the next $50 million of its average daily net assets, 1.15% on the next $50 million of its average daily net assets, 1.10% on the next $75 million of its average daily net assets, 1.05% on the next $75 million of its average daily net assets and 1.00% on its average daily net assets in excess of $500 million. For the fiscal year ended May 31, 2025, the net fee paid to the Adviser as a percentage of average net assets was 1.04%.

Water Island Event-Driven Fund pays an annual fee of 1.10% on the amount of the Fund's average net assets. For the fiscal year ended May 31, 2025, the net fee paid to the Adviser as a percentage of average net assets was 0.94%.

Water Island Credit Opportunities Fund pays an annual fee of 0.95% on the first $250 million of its average daily net assets, 0.90% on the next $500 million of its average daily net assets and 0.85% on its average daily net assets in excess of $750 million. For the fiscal year ended May 31, 2025, the net fee paid to the Adviser as a percentage of average daily net assets was 0.58%.

A discussion regarding the basis for the Board of Trustees approving the investment advisory agreement with the Adviser for each Fund is available in the Funds' Annual Financial Statements and Additional Information for the year ended May 31, 2025.

Arbitrage Fund and Water Island Event-Driven Fund have each entered into an Amended and Restated Expense Waiver and Reimbursement Agreement with the Adviser pursuant to which the Adviser has contractually agreed to waive advisory fees and/or reimburse the Funds' other expenses to the extent that total operating expenses (exclusive of taxes, interest, dividends on short positions, brokerage commissions, acquired fund fees and expenses and other costs incurred in connection with the purchase or sale of portfolio securities), exceed 1.69% of each Fund's average daily net assets allocable to Class R shares, 1.44% of each Fund's average daily net assets allocable to Class I shares, 2.44% of the Arbitrage Fund's average daily net assets allocable to Class C shares, and 1.69% of each Fund's average daily net assets allocable to Class A shares. The Amended and Restated Expense Waiver and Reimbursement Agreements for each of Arbitrage Fund and Water Island Event-Driven Fund each remain in effect until September 30, 2026 unless terminated at an earlier time by the Board of Trustees. The Adviser may recoup any waived amount from a Fund pursuant to the agreement, if such recoupment does not cause the Fund to exceed existing expense limitations in effect at the time amounts were waived, the recoupment does not cause the Fund to exceed the current expense limitation and the recoupment is done within three years after the date on which the expense was waived.

During the year ended May 31, 2025, Arbitrage Fund invested in Water Island Event-Driven Fund. The Adviser has agreed to waive the advisory fee paid by Arbitrage Fund on Arbitrage Fund's assets that are invested in Water Island Event-Driven Fund.

Water Island Credit Opportunities Fund has entered into an Amended and Restated Expense Waiver and Reimbursement Agreement with the Adviser pursuant to which the Adviser has contractually agreed to waive advisory fees and/or reimburse the Funds' other expenses to the extent that total operating expenses (exclusive of taxes, interest, dividends on short positions, brokerage commissions, acquired fund fees and expenses and other costs incurred in connection with the purchase or sale of portfolio securities), exceed 1.23% of the Fund's average daily net assets allocable to Class R shares, 0.98% of the Fund's average daily net assets allocable to Class I shares, and 1.23% of the Fund's average daily net assets allocable to Class A shares. The agreement remains in effect until September 30, 2026 unless terminated at an earlier time by the Board of Trustees. The Adviser may recoup any waived amount from a Fund pursuant to the agreement if such recoupment does not cause the Fund to exceed existing expense limitations in effect at the time amounts were waived, the recoupment does not cause the Fund to exceed the current expense limitation and the recoupment is done within three years after the date on which the expense was waived.

Portfolio Managers

Roger Foltynowicz, CFA, CAIA, John S. Orrico, CFA, and Matthew Osowiecki are portfolio managers for Arbitrage Fund. Mr. Foltynowicz is the lead portfolio manager of the Fund.

Matthew Osowiecki, Roger Foltynowicz, CFA, CAIA, Gregory Loprete, and John S. Orrico, CFA are portfolio managers for Water Island Event-Driven Fund. Mr. Osowiecki is the lead portfolio manager of the Fund.

Gregory Loprete, John S. Orrico, CFA, and Matthew Osowiecki are portfolio managers for Water Island Credit Opportunities Fund. Mr. Loprete is the lead portfolio manager of the Fund.

Roger Foltynowicz, CFA, CAIA joined the Adviser in 2003 and currently serves as a portfolio manager of Arbitrage Fund (since January 2005) and Water Island Event-Driven Fund (since October 2010). Prior to being promoted to portfolio manager, Roger Foltynowicz was a senior equity analyst for the Funds. Mr. Foltynowicz received a Master of Science degree from Pace University in 2006 with a major in Investment Management, and a bachelor's degree from Presbyterian College in 1999 with a major in Business Administration. He received the Chartered Alternative Investment Analyst (CAIA) designation in 2011 and the Chartered Financial Analyst (CFA) designation in 2017.

Gregory Loprete joined the Adviser in 2009 and currently serves as a portfolio manager of Water Island Event-Driven Fund (since October 2010) and Water Island Credit Opportunities Fund (since October 2012). Prior to joining the Adviser, Mr. Loprete worked at Keefe, Bruyette & Woods as a Convertible and Preferred Trader where he evaluated, implemented, and managed convertible and capital structure investments. From 2007 to 2008, Mr. Loprete was a Director in the Convertible Arbitrage Group at Ramius Capital Group, LLC, where he served as co-manager and trader for the firm's US Convertible Arbitrage Portfolio. From 2003 to 2007, Mr. Loprete was a Senior Convertible Analyst and Convertible Banking Liaison at SG Cowen & Company. Mr. Loprete received a Master of Business Administration degree in Finance from New York University in 1993, and a bachelor's degree from the University of Delaware in 1987 with a major in English Literature and a minor in Economics.

John S. Orrico, CFA serves as Co-Chief Investment Officer of the Adviser and also serves as the President and Chairman of the Board of Trustees of The Arbitrage Funds and AltShares Trust, an open-end management investment company which is part of the same fund complex as The Arbitrage Funds. He currently serves as a portfolio manager of Arbitrage Fund (since September 2000), Water Island Event-Driven Fund (since March 2018), and Water Island Credit Opportunities Fund (since January 2018). Prior to organizing the Adviser in January 2000, Mr. Orrico assisted in the management of private trusts and entities employing merger arbitrage strategies. Mr. Orrico received a bachelor's degree from Georgetown University in 1982, with a double major in Finance and International Management. He received the Chartered Financial Analyst designation in 1988.

Matthew Osowiecki joined the Adviser in 2007 and currently serves as Co-Chief Investment Officer of the Adviser and a portfolio manager of Arbitrage Fund (since June 2016), Water Island Event-Driven Fund (since September 2023), and Water Island Credit Opportunities Fund (since September 2025). Prior to being promoted to portfolio manager of the Adviser in 2016, Mr. Osowiecki served as a senior equity analyst. Before joining the Adviser, Mr. Osowiecki worked in the Investment Product Division of The Hartford and as a project manager in commercial development. Mr. Osowiecki received a Bachelor of Science in Finance from the University of Connecticut.

The Funds' SAI provides additional information about each portfolio manager's compensation, other accounts managed by the portfolio manager and the portfolio manager's ownership of securities in the Funds he manages.

DISTRIBUTION ARRANGEMENTS

Distributor

ALPS Distributors, Inc. (the "Distributor") serves as principal underwriter for the Funds and, as such, is the exclusive agent for the distribution of shares of the Funds.

THE ARBITRAGE FUNDS

Distribution Plan

Arbitrage Fund, Water Island Event-Driven Fund and Water Island Credit Opportunities Fund each has adopted a Rule 12b-1 plan for Class R shares, which allows the Fund to pay distribution and other fees for the sale and distribution of Class R shares and for services provided to shareholders. The maximum level of distribution expenses is 0.25% per year of a Fund's average daily net assets allocable to Class R shares. As these fees are paid out of a Fund's assets on an on-going basis, over time these fees will increase the cost of an investment in Class R shares and may cost you more than paying other types of sales charges.

Arbitrage Fund has adopted a Rule 12b-1 plan for Class C shares (the "Plan"), which allows the Fund to pay distribution and other fees for the sale and distribution of Class C shares and for services provided to shareholders. The Plan permits the Fund to make payments at an annual rate of up to 0.75% of the Fund's average daily net assets attributable to its Class C shares for expenses incurred in the promotion and distribution of the Fund's shares. In addition, the Plan permits the Fund to make payments at an annual rate of up to 0.25% of the Fund's Class C shares for expenses incurred in connection with the provision of shareholder support or administrative services for the Fund's Class C shares. As these fees are paid out of the Fund's assets on an on-going basis, over time these fees will increase the cost of an investment in Class C shares and may cost you more than paying other types of sales charges. Under the terms of the Plan, the Fund is authorized to make payments to the principal distributor of the Fund for remittance to broker-dealers, retirement platforms, and other financial intermediaries as compensation for distribution and/or shareholder services performed by such entities for their customers who are investors in the Fund. Financial intermediaries may from time to time be required to meet certain criteria in order to receive 12b-1 fees. The Fund's principal distributor is entitled to retain all fees paid under the Plan for the first 12 months on any investment in Class C Shares to recoup its expenses with respect to the payment of commissions on sales of Class C Shares. Financial intermediaries will become eligible for compensation under the Class C Plan beginning in the 13th month following the purchase of Class C Shares. The Fund's principal distributor is entitled to retain some or all fees payable under a Plan in certain circumstances, including when there is no broker of record or when certain qualification standards have not been met by the broker of record.

Arbitrage Fund, Water Island Event-Driven Fund, and Water Island Credit Opportunities Fund each has adopted a Rule 12b-1 plan for Class A shares, which allows the Fund to pay distribution and other fees for the sale and distribution of Class A shares and for services provided to shareholders. The maximum level of distribution expenses is 0.25% per year of a Fund's average daily net assets allocable to Class A shares. As these fees are paid out of a Fund's assets on an on-going basis, over time these fees will increase the cost of an investment in Class A shares and may cost you more than paying other types of sales charges.

NET ASSET VALUE

The net asset value ("NAV") per share of each Class of shares of a Fund will be determined on each day the NYSE is open for business and will be computed by determining the aggregate market value of all assets of the Fund less its liabilities, and then dividing by the total number of shares outstanding. The NYSE is closed on weekends and most national holidays. The determination of NAV for a particular day is applicable to all applications for the purchase of shares, as well as all requests for the redemption of shares, received before the close of trading on the NYSE on that day (normally 4:00 p.m. Eastern Time).

Each Fund generally values portfolio securities at market value. If market quotations are not available or reliable, a Fund will value securities at their fair value as determined in good faith under the supervision of the Board of Trustees. The Board of Trustees has designated the Adviser as each Fund's "valuation designee" responsible for the performance of the Funds' fair valuations determinations. The fair value of a security is the amount which a Fund might reasonably expect to receive upon a current sale. The fair value of a security may differ from the last quoted price and a Fund may not be able to sell a security at the fair value. Market quotations may not be available, for example, if trading in particular securities was halted during the day and not resumed prior to the close of trading on the NYSE. Market quotations of foreign securities from the principal markets in which they trade may not be reliable if events or circumstances that may affect the value of portfolio securities occur between the time of the market quotation and the close of trading on the NYSE. If a significant event that affects the valuation of a foreign security occurs between the close of the foreign security's primary exchange and the time the Funds calculate their NAV, the Funds will fair value the foreign security to account for this discrepancy. In addition, since certain foreign securities may trade on weekends or days when a Fund does not price its shares, the value of these securities may change on days when Fund shares cannot be purchased or redeemed.

HOW TO PURCHASE SHARES

The availability of certain sales charge reductions and waivers may depend on whether you purchase your shares directly from the Fund or through a financial intermediary. Different intermediaries may impose different sales charges (including potential reductions in or waivers of sales charges) from those listed below. Such intermediary-specific sales charge variations are described in Appendix A to this prospectus, titled "Intermediary-Specific Sales Charge Reductions and Waivers." Appendix A is incorporated by reference into (or legally considered part of) this prospectus.

In all instances, it is the shareholder's responsibility to notify the Fund or the shareholder's financial intermediary at the time of purchase of any relationship or other facts qualifying the shareholder for sales charge reductions or waivers. For reductions and waivers not available through

a particular intermediary, shareholders will have to purchase Fund shares directly from the Fund or through another intermediary to receive these reductions or waivers.

It is also the shareholder's responsibility to ensure that their address and other pertinent contact information is current with the Fund's transfer agent or the shareholder's financial intermediary to avoid dormancy. If such information becomes inaccurate and contact cannot be established, there is the risk of escheatment of a shareholder's assets. Every state has adopted an unclaimed property (or escheat) law, which generally provides that a holder of unclaimed property must escheat the property to the state after it has remained unclaimed by its owner for a certain period.

Eligible Purchases

Purchases, exchanges, and redemptions of Class C (Arbitrage Fund only) and Class A shares may generally be effected only through institutional channels, such as broker-dealers, retirement platforms, and other financial intermediaries which have established an agreement with the Funds' distributor. Financial intermediaries may charge additional fees for their services, including ticket and/or transaction fees for processing trades. You should contact your financial intermediary or refer to your plan documents for information on how to invest in the Fund. Requests must be received in good order by the Fund or its agent (financial intermediary or plan sponsor, if applicable) prior to the close of the regular trading session of the NYSE in order to receive that day's NAV.

Front-End Sales Charges - Class A Shares

The offering price of Class A Shares is the NAV next calculated after the applicable Fund receives your request, plus the front-end sales charge. The amount of any front-end sales charge included in your offering price varies depending on the amount of your investment.

Front-End Sales Charges - Arbitrage Fund

* If you are in a category of investors who may purchase Fund shares without a front-end sales charge, you may be subject to a deferred sales charge of up to 1.00% if you redeem your shares within 18 months of purchase.

** The Distributor, at its own discretion, will pay a commission to dealers on purchases of $250,000 or more as follows: 1.00% on sales of $250,000 up to $2,999,999, 0.50% on sales of $3,000,000 up to $9,999,999, and 0.25% on sales of $10,000,000 or more. Payments of 12b-1 fees to broker-dealers and others who receive a finder's fee will begin after the Class A Shares have been held for one year.

*** Dealer's Concession will be calculated based on the sales charge paid by shareholders, taking into account applicable rights of accumulation.

Front-End Sales Charges - Water Island Event-Driven Fund and Water Island Credit Opportunities Fund

* If you are in a category of investors who may purchase Fund shares without a front-end sales charge, you may be subject to a deferred sales charge of up to 1.00% if you redeem your shares within eighteen months of purchase.

** The Distributor, at its own discretion, will pay a commission to dealers on purchases of $250,000 or more as follows: 1.00% on sales of $250,000 up to $2,999,999, 0.50% on sales of $3,000,000 up to $9,999,999, and 0.25% on sales of $10,000,000 or more. Payments of 12b-1 fees to broker-dealers and others who receive a finder's fee will begin after the Class A shares have been held for one year.

For more information on how to determine what share class is most appropriate for you, please see "Choosing a Share Class," below, or consult your broker or other financial intermediary.

You may qualify for reduced sales charges or sales charge waivers. Information about certain intermediary-specific sales charges and sales charge waivers is contained in Appendix A to this prospectus and is available on the Funds' website at https://arbitragefunds.com/resources. For other inquiries, please consult your broker or other financial intermediary to see whether you qualify for a reduction or waiver of the sales charge. If you believe that you may qualify for a reduction or waiver of the sales charge, you should discuss this matter with your broker or other financial intermediary. To qualify

THE ARBITRAGE FUNDS

for these reductions or waivers, you or your financial intermediary must provide sufficient information at the time of purchase to verify that your purchase qualifies for such treatment. This information could be used to aggregate, for example, holdings in personal or retirement accounts, Fund shares owned by your immediate family members, and holdings in accounts at other brokers or financial intermediaries. The Funds or your financial intermediary may request documentation from you in order to verify your eligibility for a breakpoint discount. This information may include account statements and records regarding Fund shares held at all financial intermediaries by you and members of your immediate family. In addition to breakpoint discounts, the following sections describe other circumstances in which sales charges are waived or otherwise may be reduced.

Waiver of Front-End Sales Charge - Class A Shares

Certain investors may be eligible for a waiver of the sales charges due to the nature of the investors and/or the reduced sales efforts necessary to obtain their investments. The front-end sales charge may be waived on Class A Shares purchased by:

● Accounts advised by the Adviser;

● Persons repurchasing shares they redeemed within the last 60 days (see "Repurchase of Class A Shares");

● Employees, officers, and directors, and members of their immediate family, of the Adviser;

● Investors who acquire Class A Shares in one Fund through the exchange of Class A Shares in another Fund (See "Exchanging Shares");

● Institutional retirement plans whereby an arrangement is in place with the financial intermediary to offer those shares at NAV;

● Asset allocation programs whereby an arrangement is in place with the financial intermediary to offer those shares at NAV;

● Other specific dealers, financial institutions, or programs whereby an arrangement is in place with the financial intermediary to offer those shares at NAV;

● Registered representatives and other employees of certain financial intermediaries (and their immediate family members) having selling agreements with the Adviser or the Distributor;

● Broker-dealer sponsored wrap program accounts and/or fee-based accounts maintained for clients of certain financial intermediaries who have entered into selling agreements with the Distributor;

● Financial intermediary supermarkets and fee-based platforms. Other fees may be charged by the service-provider sponsoring the fund supermarket, and transaction charges may apply to purchases and sales made through a broker-dealer; and

● Other investors as deemed appropriate by the Adviser.

Additional information on intermediary-specific sales charge waivers and variations are described in Appendix A to this prospectus, "Intermediary-Specific Sales Charge Reductions and Waivers."

Repurchase of Class A Shares

You may repurchase any amount of Class A Shares of Arbitrage Fund, Water Island Event-Driven Fund and Water Island Credit Opportunities Fund at NAV (without the normal front-end sales charge), up to the limit of the value of any amount of Class A Shares (other than those which were purchased with reinvested dividends and distributions) that you redeemed within the past 60 days. In effect, this allows you to reacquire shares that you may have had to redeem, without repaying the front-end sales charge. To exercise this privilege, the Fund must receive your purchase order within 60 days of your redemption. In addition, you must notify your investment professional or institution when you send in your purchase order that you are repurchasing shares. Certain tax rules may limit your ability to recognize a loss on the redemption of your Class A Shares, and you should consult your tax advisor if recognizing such a loss is important to you.

Rights of Accumulation

In calculating the appropriate sales charge rate, this right allows you to add the value of the Class A and Class C Shares you already own to the amount that you are currently purchasing. A Fund will combine the value of your purchases with the value of any Class A and Class C Shares you purchased previously for (i) your account, (ii) your spouse's account, (iii) a joint account with your spouse or (iv) your minor children's trust or custodial accounts. A fiduciary purchasing shares for the same fiduciary account, trust or estate may also use this right of accumulation. The value of your accumulated shares equals the cost or current value of those shares, whichever is higher. The current value of shares is determined by multiplying the number of shares by their highest current public offering price. To receive a reduction or waiver of your sales charge, you must advise your financial intermediary or the Fund at the time of purchase of the existence of other accounts and/or holdings eligible to be aggregated to reduce or eliminate the sales load. You may be required to provide records, such as account statements, regarding the Fund shares held by you or related accounts at the Fund or at other financial intermediaries in order to verify your eligibility for a breakpoint discount as the Funds, their transfer agent and financial intermediaries may not maintain this information. You will receive the reduced sales load only on the additional purchases and not retroactively on previous purchases. The Funds may amend or terminate this right of accumulation at any time.

Letter of Intent

You may combine Class A Share purchases of any Fund over a 13-month period and receive the same sales charge as if all shares had been purchased at once by signing a Letter of Intent (the "Letter"). You must inform your financial intermediary or the Fund that you have a Letter each time you make an investment. Purchases resulting from the reinvestment of dividends and distributions do not apply toward fulfillment of the Letter. The Funds will

only consider the value of Class A Shares sold subject to a sales charge. Shares purchased within 90 days of the date you sign the Letter may be used as a credit toward completion, but the reduced sales charge will only apply to new purchases made on or after that date. The purchase price of these prior purchases will not be adjusted. The 13-month period begins on the date of the first purchase, including those purchases made in the 90-day period before the date of the Letter.

You are not legally bound by the terms of your Letter to purchase the amount of your shares stated in the Letter. The Letter does, however, authorize the Fund to hold in escrow 5% of the total amount you intend to purchase. If you do not complete the total intended purchase of Class A Shares at the end of the 13-month period, the Fund's transfer agent will redeem the necessary portion of the escrowed shares to make up the difference between the reduced rate sales charge (based on the amount you intended to purchase) and the sales charge that would normally apply (based on the actual amount you purchased). Any remaining escrowed shares will be released to you.

Combined Purchase/Quantity Discount Privilege

When calculating the appropriate sales charge rate, a Fund will combine same-day purchases of Fund shares (that are subject to a sales charge) made by you, your spouse, and your minor children (under age 21). This combination also applies to Fund shares you purchase with a Letter of Intent.

General Information about Sales Charges

Your securities dealer is paid a commission when you buy your shares and is paid a servicing fee as long as you hold your shares.

From time to time, some financial institutions may be reallowed up to the entire sales charge. Firms that receive a reallowance of the entire sales charge may be considered underwriters for the purpose of federal securities law.

From time to time, one or more promotional incentive programs for dealers may be instituted. Under any such program, dealers may receive cash or non-cash compensation as recognition for past sales or encouragement for future sales that may include merchandise, travel expenses, prizes, meals, lodgings, and gifts that do not exceed $100 per year, per individual.

Information regarding the Funds' sales charges may be obtained free of charge by calling, toll-free, at (800) 295-4485.

Contingent Deferred Sales Charge

If your account value, including the amount of your current investment, totals $250,000 or more in Class A shares of Arbitrage Fund or $250,000 or more in Class A shares ($500,000 or more in Class A shares purchased prior to June 30, 2018, determined on a first-in, first-out ("FIFO") method) of Water Island Event-Driven Fund or Water Island Credit Opportunities Fund, you will not pay a front-end sales charge on the current investment amount. However, if you sell these shares (for which you did not pay a front-end sales charge) within 18 months of purchase, you will pay a contingent deferred sales charge ("CDSC") of up to 1.00%. The amount of the CDSC is determined as a percentage of the lesser of the current market value or the cost of the shares being redeemed. The CDSC primarily goes to the distributor as reimbursement for the portion of the dealer concession paid to financial intermediaries. This sales charge does not apply to exchanges of Class A Shares of one Fund for Class A Shares of another Fund.

There is a 1% CDSC on Class C shares which you sell within 12 months of purchase. The amount of the CDSC is determined as a percentage of the original purchase price of the shares being redeemed. The CDSC primarily goes to the Fund's distributor as reimbursement for the portion of the dealer concession paid to financial intermediaries.

The Fund will use the FIFO method to determine the holding period for the CDSC. The date of the redemption will be compared to the earliest purchase date of shares held in the redeeming shareholder's account. The CDSC will be charged if the holding period is less than one year, using the anniversary date of a transaction to determine the "one year" mark. As an example, shares purchased on December 1, 2024 would be subject to the CDSC if they were redeemed prior to December 1, 2025. On or after December 1, 2025, they would not be subject to CDSC.

Class A shares acquired by reinvestment of dividends are not subject to the CDSC. CDSC waivers are available in certain circumstances. For information regarding waivers, please see "Waiver of CDSC" below.

Waiver of CDSC

A Fund may waive the imposition of a CDSC on redemption or exchange of Fund shares under certain circumstances and conditions, including without limitation, the following:

● Redemptions following the death or permanent disability (as defined by Section 72(m)(7) of the Internal Revenue Code) of a shareholder if made within one year of death or the initial determination of permanent disability. The waiver is available only for shares held at the time of death or initial determination of permanent disability.

● Required minimum distributions from a tax-deferred retirement plan or an individual retirement account ("IRA") as required under the Internal Revenue Code. The waiver of the CDSC for required distributions will be as a percentage of assets held in the Fund.

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If you think you may be eligible for a CDSC waiver, contact your financial intermediary. You must notify the Fund prior to the redemption request to ensure your receipt of the waiver.

Choosing a Share Class

Arbitrage Fund offers four Classes of shares, Class R, Class I, Class C, and Class A. Water Island Event-Driven Fund and Water Island Credit Opportunities Fund each offer three Classes of shares, Class R, Class I, and Class A. The Classes, which represent interests in the same portfolio of investments and have the same rights, differ primarily in the expenses to which they are subject and required investment minimums (the minimum investment amounts are subject to waiver, as discussed below).

Class A shares and Class R shares are subject to an annual 12b-1 fee of up to 0.25% of a Fund's average daily net assets allocable to that share class. Class C shares are subject to an annual 12b-1 fee of up to 1.00% of a Fund's average daily net assets allocable to Class C shares. Class I shares are not subject to any 12b-1 fees.

Class A shares are sold subject to a front-end sales charge. Class R shares and Class I shares of a Fund are no-load. This means that shares may be purchased without the imposition of any sales charge. There is a 1% CDSC on Class C shares if you sell within 12 months of a purchase. A CDSC may be imposed on certain purchases of Class A shares, as described above in "Contingent Deferred Sales Charge."

Purchases, exchanges and redemptions of Class A and Class C shares may generally be effected only through institutional channels, such as broker-dealers, retirement platforms, and other financial intermediaries which have established an agreement with the Funds' Distributor. Financial intermediaries may charge additional fees for their services, including ticket and/or transaction fees for processing trades. In addition, certain financial intermediaries may have share class exchange programs whereby a shareholder of a Fund's Class C shares may have their shares converted at net asset value to Class A shares of the Fund if the shares are no longer subject to a CDSC. You should contact your financial intermediary or refer to your plan documents for information on how to invest in the Fund. Requests must be received in good order by the Fund or its agent (financial intermediary or plan sponsor, if applicable) prior to the close of the regular trading session of the NYSE in order to receive that day's NAV.

Class I shares are available only to shareholders who invest directly in a Fund or who invest through a broker-dealer, financial institution or servicing agent that does not receive a distribution fee from the Fund or the Adviser. Class I shares may also be available on brokerage platforms of firms that have agreements with the Funds' distributor to offer such shares solely when acting as an agent for an investor. An investor transacting in Class I shares in these programs may be required to pay a commission and/or other forms of compensation to the broker. Shares of each Fund are available in other share classes that have different fees and expenses.

There is generally also a higher minimum initial investment requirement with respect to Class I shares in "Minimum Investments Amounts," below.

Shares of a Fund are available for purchase from the Fund every day the NYSE is open for business, at the NAV (or offering price, for Class A shares) next calculated after receipt of the purchase request in good order. Each Fund mails you confirmations of all purchases or redemptions of Fund shares.

Minimum Investment Amounts

Class R shares* - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments other than investments through a Fund's Automatic Investment Plan, which has a $100 minimum for investments.

Class I shares* - The minimum initial investment for all types of accounts is $100,000. There is no minimum for subsequent investments other than investments through a Fund's Automatic Investment Plan, which has a $100 minimum for investments.

Class C shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments in Class C shares.

Class A shares - The minimum initial investment for all types of accounts is $2,000. There is no minimum for subsequent investments in Class A shares.

Each Fund has granted the authority to the Adviser, in its sole discretion, to waive the initial investment minimums for the Class I Shares. The Adviser, though granted sole discretion by each Fund, has committed to consult the Fund's Chief Compliance Officer prior to authorizing any such waivers.

* Additionally, there will be no investment minimums for either share class for both omnibus and non-omnibus accounts held by financial institutions for the benefit of their clients who purchase shares through investment programs such as (1) employee benefit plans, like 401(k) retirement plans; (2) fee-based advisory or "wrap" programs; (3) mutual fund supermarkets or platforms such as those maintained by Charles Schwab, Fidelity or other broker-dealers; (4) consulting firms; and (5) trust companies.

Shares of each Fund are offered on a continuous basis. Each Fund reserves the right, in its sole discretion, to reject any application to purchase shares.

When Orders Are Processed

All shares will be purchased at the NAV per share next determined after a Fund or its agent receives your purchase request in good order. All requests received in good order by a Fund before 4:00 p.m. (Eastern Time) will be executed on that same day. Requests received after 4:00 p.m. will be processed on the next business day.

Purchase through Brokers and Other Intermediaries

You may use your broker, dealer, financial institution or other servicing agent to purchase shares of a Fund if the servicing agent has an agreement with the Fund's distributor. Please note that such agents may charge additional fees for their services, including ticket and/or transaction fees for processing trades. See Appendix A - "Intermediary Sales Charge Reductions and Waivers" for information on whether you may qualify for certain waivers or reductions in sales charges offered by a particular intermediary. Depending on your servicing agent's arrangements with a Fund, you may qualify to purchase Class I shares, which are subject to lower ongoing expenses. Please see "Choosing a Share Class" above for more information or contact your servicing agent. You should also note that your servicing agent may become a record shareholder of a Fund requiring all purchase and redemption requests to be sent through your servicing agent. Finally, various servicing agents use procedures and impose restrictions that may be in addition to, or different from those applicable to investors purchasing shares directly from a Fund. You should carefully read the program materials provided to you by your servicing agent.

Certain servicing agents may provide administrative services (such as sub-transfer agency, record-keeping or shareholder communications services) to investors purchasing shares of a Fund through such companies. The Adviser or a Fund may pay fees to these servicing agents for their services. They may also compensate servicing agents in connection with the sale of Fund shares. These payments may create an incentive for the servicing agents to recommend that you purchase Fund shares.

Purchase by Wire

If you wish to wire money to invest in Class R shares or Class I shares of a Fund, please call the Funds at 1-800-295-4485 to notify the Funds that a wire transfer is coming. There are no direct purchases for Class C or Class A shares of a Fund. You may use the following instructions:

The Arbitrage Funds United Missouri Bank

For further credit to: Name/Fund #/Account #

If the shareholder would like to make a fund purchase via wire transfer, he/she must contact the Fund's transfer agent for proper wire instructions.

Automatic Investment Plan

Class R and Class I shareholders may participate in the Funds' Automatic Investment Plan, an investment plan that automatically debits money from your bank account and invests it in the Fund through the use of electronic funds transfers or automatic bank drafts. After making an initial investment of at least $2,000, you may elect to make subsequent investments by transfers of a minimum of $100 on specified days of each month into your established Fund account. Please contact the Funds at 1-800-295-4485 for more information about the Automatic Investment Plan.

Retirement Plans

You may purchase shares of a Fund for your individual retirement plans. Please call the Funds at 1-800-295-4485 for the most current listing and appropriate disclosure documentation on how to open a retirement account.

The Funds do not accept cash, credit card checks, money orders, Travelers checks, third-party checks, or bearer forms securities of any kind.

REDEMPTIONS

Redemptions for Class C and Class A shares, like purchases, may generally be effected only through retirement plans, broker-dealers and other financial intermediaries. Please contact your financial intermediary or refer to the appropriate plan documents for details. Your financial intermediary may charge a processing or service fee in connection with the redemption of shares. The redemption price of Class C and Class A shares subject to a CDSC will be

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reduced by any applicable CDSC. The CDSC may be deducted from your redemption proceeds or from your account balance. If no preference is stated at the time of redemption, the charge will be deducted from the redemption proceeds.

Written Redemption Requests

You will be entitled to redeem all or any portion of the Class R shares or Class I shares credited to your account by submitting a written request for redemption to:

Regular Mail
The Arbitrage Funds
c/o SS&C GIDS
P.O. Box 219842
Kansas City, MO 64121-9842
Express/Overnight Mail
The Arbitrage Funds
c/o SS&C GIDS
801 Pennsylvania Avenue
Suite 219842
Kansas City, MO 64105-1307

Redeeming by Telephone

You may redeem Class R shares or Class I shares by telephone having a value of up to a maximum of $25,000 in any 30-day period. The proceeds will be sent by mail to the address designated on your account or wired directly to your existing account in any commercial bank or brokerage firm in the U.S. as designated on your application. To redeem by telephone, call 1-800-295-4485. The redemption proceeds normally will be sent by mail or by wire within three business days after receipt of your telephone instructions. IRA accounts are not redeemable by telephone.

The telephone redemption privilege is automatically available to you unless you have instructed the Funds to remove this privilege from your account.

The telephone redemption privilege will not be available with respect to your account if the name(s) or the address on the account has been changed within the previous 30 days. Neither the Funds, the transfer agent, nor their respective affiliates will be liable for complying with telephone instructions they reasonably believe to be genuine or for any loss, damage, cost or expenses in acting on such telephone instructions and you will be required to bear the risk of any such loss. Each Fund or the transfer agent, or both, will employ reasonable procedures to determine that telephone instructions are genuine. If a Fund and/or the transfer agent do not employ these procedures, they may be liable to you for losses due to unauthorized or fraudulent instructions. These procedures may include, among others, requiring forms of personal identification prior to acting upon telephone instructions, providing written confirmation of the transactions and/or tape recording telephone instructions.

Wire Redemptions

If you request your redemption proceeds to be sent by wire transfer, you will be required to pay a $15 wire transfer fee to cover costs associated with the transfer. In addition, your bank may impose a charge for receiving wires.

Systematic Withdrawal Plan

If an account has a current value of at least $10,000, you may adopt a Systematic Withdrawal Plan to provide for monthly, quarterly, or other periodic checks for any designated amount of $500 or more. If you wish to open a Systematic Withdrawal Plan, please contact the Funds at 1-800-295-4485.

When Redemptions are Sent

Once a Fund receives your redemption request from a financial intermediary in "good order" as described below, it will issue a check based on the next determined NAV following your redemption request. If you purchase shares using a check and then soon after request a redemption, the applicable Fund will honor the redemption request but will not mail the proceeds until your purchase check has cleared (usually within 15 days).

A Fund typically expects to pay out redemption proceeds within seven days of the redemption request in all cases. In addition, a Fund can suspend redemptions and/or postpone payments or redemption proceeds beyond seven days at times when the NYSE is closed or during emergency circumstances, as determined by the SEC.

Good Order

Your redemption request will be processed if it is received from a financial intermediary in "good order." To be in good order, the following conditions must be satisfied:

● The request should indicate the name of the applicable Fund;

● The request should indicate the number of shares or dollar amount to be redeemed;

● The request must identify the name(s) on your account and your account number; and

● The request should be signed by you and any other person listed on the account, exactly as the shares are registered.

See below for a discussion on when the signature(s) on the request must be guaranteed by an eligible medallion signature guarantor.

When You Need Signature Guarantees

A signature guarantee assures that a signature is genuine and protects you from unauthorized account transfers.

A signature guarantee is required if:

● you request a redemption to be made payable to a person not on record with the Funds;

● you request that a redemption be mailed to an address other than that on record with the Funds, or a change of address request was received by the transfer agent within the last 30 days;

● when establishing or modifying certain services on an account; or

● the shares to be redeemed over any 30-day period have a value of greater than $25,000.

Signatures may be guaranteed by any eligible guarantor institution (including banks, brokers and dealers, credit unions, national securities exchanges, registered securities associations, clearing agencies and savings associations) or by completing a supplemental telephone redemption authorization form. Contact the Funds to obtain this form. Further, in some cases, documentation may be required to change the designated account if shares are held by a corporation, fiduciary, or other organization. A notary public cannot guarantee signatures.

● A Medallion signature guarantee is designed to protect you and The Arbitrage Funds from fraud by verifying your signature. You may need to have your signature guaranteed in certain situations, such as:

● Written requests: (1) to redeem over $100,000 or (2) to wire redemption proceeds when prior bank account authorization is not on file.

● Remitting redemption proceeds to any person, address, or bank account not on file.

● Transferring redemption proceeds to an Arbitrage Fund account with a different registration (name or ownership) from yours.

● Establishing certain services after the account is opened.

● The signature guarantee must be obtained from a financial institution that is a participant in a Medallion signature guarantee program. You can obtain a Medallion signature guarantee from most banks, savings institutions, broker-dealers, and other guarantors acceptable to The Arbitrage Funds. When obtaining a Medallion signature guarantee, please discuss with the guarantor the dollar amount of your proposed transaction. It is important that the level of coverage provided by the guarantor's stamp covers the dollar amount of the transaction or it may be rejected. We cannot accept guarantees from notaries public or organizations that do not provide reimbursement in the case of fraud.

Retirement Plans

If you are redeeming shares from an IRA or other retirement plan, you must indicate on your redemption request whether the Funds should withhold federal income tax. Unless you elect in your redemption request that you do not want to have federal tax withheld, the redemption will be subject to withholding.

Redeeming through Brokers

If shares of the Funds are held by a broker-dealer, financial institution, or other servicing agent, you must contact that servicing agent to redeem shares of the Funds. The servicing agent may charge a fee for this service.

Low Balances and Redemption "In Kind"

If at any time your account balance falls below $1,000 for Class R shares or $50,000 for Class I shares, the Funds may notify you that, unless the account is brought up to at least that amount, your account could be closed. The Funds may, within 30 days, redeem all of your shares and close your account by sending you a check to the address of record on your account. In addition, with respect to Class I shares, the Funds may convert your Class I shares into Class R shares. Any such conversion will occur at the relative NAV of the two share Classes, without the imposition of any fees or other charges. Where a retirement plan or other financial intermediary holds Class I shares on behalf of its participants or clients, the above policy applies to any such participants or clients when they roll over their accounts with the retirement plan or financial intermediary into an individual retirement account and they are not otherwise eligible to purchase Class I shares.

If at any time your account balance falls below $1,000 for Class C shares, Arbitrage Fund or its agents may notify you that, unless the account is brought up to at least that amount, your account could be closed. The Fund or its agents may, within 30 days, redeem all of your shares and close your account by sending you a check to the address of record on your account. Any such redemption may result in a taxable event, and you may realize a gain or a loss as a result.

It is expected that payment of redemption proceeds will normally be made from uninvested cash or short-term investments, proceeds from the sale of portfolio securities, or borrowing through The Arbitrage Funds' credit facility, as described in the SAI. It is possible that stressed market conditions or large shareholder redemptions may result in the need for utilization of the Funds' ability to redeem in kind in order to meet shareholder redemption

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requests. The Funds reserve the right to pay all or part of your redemption proceeds in readily marketable securities instead of cash (redemption in-kind). Redemption in-kind proceeds will typically be made by delivering the selected securities to the redeeming shareholder within seven days after the receipt of the redemption request in good order by the Fund. Shareholders who receive a redemption "in kind" may incur costs to dispose of such securities.

Cost Basis Information

Since January 1, 2012, federal law requires that mutual fund companies report their shareholders' cost basis, gain/loss, and holding period to the Internal Revenue Service ("IRS") on the shareholders' Consolidated Form 1099s when "covered" shares of the mutual funds are sold. Covered shares are any fund and/or dividend reinvestment plan shares acquired on or after January 1, 2012.

The Funds have chosen average cost as their standing (default) tax lot identification method for all shareholders, which means this is the method the Funds will use to determine which specific shares are deemed to be sold when there are multiple purchases on different dates at differing net asset values, and the entire position is not sold at one time. The Funds' standing tax lot identification method is the method it will use to report the sale of covered shares on your Consolidated Form 1099 if you do not select a specific tax lot identification method. You may choose a method other than the Funds' standing method at the time of your purchase or upon the sale of covered shares. Please refer to the appropriate IRS regulations or consult your tax advisor with regard to your personal circumstances.

Frequent Trading Policies

Frequent purchases and redemptions of Fund shares by a shareholder may harm other Fund shareholders by interfering with the efficient management of a Fund's portfolio, increasing brokerage and administrative costs, and potentially diluting the value of their shares. Accordingly, the Funds' Board of Trustees discourages frequent purchases and redemptions of Class R, Class I, and Class A shares by reserving the right to reject any purchase order for any reason or no reason, including purchase requests from potential investors that the Funds believe might engage in frequent purchases and redemptions of Fund shares.

The right to reject an order applies to any order, including an order placed from an omnibus account, as applicable. Although the Funds have taken steps to discourage frequent purchases and redemptions of Fund shares, they cannot guarantee that such trading will not occur.

With regard to Arbitrage Fund's Class C shares, the Fund's Board of Trustees has determined not to adopt policies and procedures that discourage frequent purchases and redemptions of Fund shares because it believes that since the Class C shares have a CDSC it is unlikely that the Class C shares will experience frequent purchases and redemptions that are disruptive to the Fund. The Fund's Board of Trustees may reconsider its decision not to adopt such policies and procedures if it determines there is unusual trading in Class C shares of the Fund. In addition, the Fund reserves the right to reject any Class C purchase order for any reason or no reason, including purchase requests from potential investors that the Fund believes might engage in frequent purchases and redemptions of Fund shares. The right to reject an order applies to any order, including an order placed from an omnibus account.

EXCHANGING SHARES

Class R shares of any Fund may be exchanged for Class R shares of another Fund at their relative net asset values. Class I shares of any Fund may be exchanged for Class I shares of another Fund at their relative net asset values.

Class C shares of Arbitrage Fund may be exchanged for Class R or Class I shares of the Fund, provided (1) you meet the investment eligibility requirements for purchase of shares of the class you wish to exchange into, and (2) you have held your Class C shares for longer than twelve months.

Class A shares of Arbitrage Fund, Water Island Event-Driven Fund, and Water Island Credit Opportunities Fund may be exchanged for Class A shares of another Fund at their relative net asset values, provided you have held such shares for at least thirty days. For purposes of calculating the CDSC, such shares will be deemed to have been held since the date the shares being exchanged were initially purchased. Class A shares of Arbitrage Fund, Water Island Event-Driven Fund and Water Island Credit Opportunities Fund may be exchanged for Class R or Class I shares of the same Fund, provided (1) you meet the investment eligibility requirements for purchase of shares of the class you wish to exchange into, and (2) for Class A shares subject to a CDSC, you have held such shares for longer than 18 months, with respect to shares of Arbitrage Fund, Water Island Event-Driven Fund, and Water Island Credit Opportunities Fund.

If you qualify as a purchaser of Class I shares, but your account is invested in Class R, C, or A shares, you may convert such shares to Class I shares based on the relative net asset values of the two Classes on the conversion date.

Certain financial intermediaries may have share class exchange programs whereby a shareholder of a Fund's Class C shares may have their shares converted at net asset value to Class A shares of the Fund if the shares are no longer subject to a CDSC.

The Fund reserves the right to reject any exchange request for any reason or no reason. You may have a taxable gain or loss as a result of an exchange because the Internal Revenue Code treats an exchange as a sale of shares. To exchange shares:

1. Read this prospectus carefully.

2. Determine the number of shares you want to exchange keeping in mind that exchanges are subject to a $1,000 minimum.

3. Contact your financial intermediary, or call SS&C GIDS at (800) 295-4485. You may also make an exchange by writing to The Arbitrage Funds, c/o SS&C GIDS, P.O. Box 219842, Kansas City, Missouri 64121-9842.

CONVERSION OF SHARES

Effective on or about September 30, 2021 (the "Effective Date"), approximately eight years after purchase, Class C shares of Arbitrage Fund will automatically convert to Class A shares of the Fund. The Class C share conversions will occur approximately once each month (on the "Class C Conversion Date") on the basis of the relative net asset value of the shares of the two applicable classes, without the imposition of any sales load, fee, or other charge. The Class C share conversions will not be deemed a purchase or sale of the shares for U.S. federal income tax purposes. The Class C Conversion Date for dividend reinvestment shares will be calculated taking into account the length of time the shares underlying the dividend reinvestment shares were outstanding. Class C shares held through a financial intermediary in an omnibus account will be converted into Class A shares only if the intermediary can document that the shareholder has met the required holding period. It is the financial intermediary's (and not the Fund's) responsibility to keep records and to ensure that the shareholder is credited with the proper holding period. Not all financial intermediaries are able to track purchases to credit individual shareholders' holding periods. In particular, group retirement plans held through third party intermediaries that hold Class C shares in an omnibus account in certain instances do not track participant level share lot aging. In such instances, the automatic conversion of Class C shares to Class A shares will occur approximately eight years after the Effective Date. Please consult with your financial intermediary about your eligibility to exercise this conversion privilege.

PAYMENTS TO FINANCIAL INTERMEDIARIES

For certain share classes, the Funds and/or the Adviser make payments to certain financial intermediaries in connection with the promotion and sale of shares of the Funds and as compensation for shareholder-related services, including administrative, sub-transfer agency, recordkeeping, and shareholder communications services. The Funds and the Adviser also pay such compensation to make shares of the Funds available to investors through certain fund platforms, supermarkets or similar programs or for services provided in connection with such platforms, supermarkets. and programs. These payments generally benefit the Funds and may provide applicable financial intermediaries with an incentive to recommend sales of shares of the Funds over other potential investments.

The Funds and the Adviser compensate financial intermediaries differently depending upon the level and type of services provided by such financial intermediaries. The compensation paid to a financial intermediary may be based on a variety of factors, including average assets under management in accounts distributed and/or serviced by the financial intermediary, gross sales by the financial intermediary and/or the number of accounts serviced by the financial intermediary that invest in the Funds. Compensation paid by a Fund for distribution-related expenses are made from the Fund's Rule 12b-1 fees. Compensation paid by the Adviser or its affiliates includes amounts from the Adviser's or its affiliates' own resources and constitute what is sometimes referred to as "revenue sharing."

Compensation received by a financial intermediary from a Fund or the Adviser may include payments for marketing and/or training expenses incurred by the financial intermediary, including expenses incurred by the financial intermediary in educating (itself and) its salespersons with respect to Fund shares. For example, such compensation may include reimbursements for expenses incurred in attending educational seminars regarding a Fund, including travel and lodging expenses. It may also cover costs incurred by financial intermediaries in connection with their efforts to sell Fund shares, including costs incurred compensating (registered) sales representatives and preparing, printing and distributing sales literature.

Any compensation received by a financial intermediary, whether from the Funds or the Adviser, and the prospect of receiving such compensation provide the financial intermediary with an incentive to recommend shares of the Funds over other potential investments. You should ask your financial intermediary for details about any such payments it receives from the Funds or the Adviser, or any other fees, expenses, or commissions your financial intermediary may charge you in addition to those disclosed in this prospectus.

A Fund's shares may be available for purchase and sale on brokerage and other financial intermediary platforms of firms that have agreements with the Funds' distributor to offer such shares solely when acting as an agent for the investor. Investors that purchase and/or sell shares of a Fund through brokers or other financial intermediaries may be required to pay commissions and/or other types of compensation to such brokers or other financial intermediaries in connection with such purchases or sales in an amount determined and separately disclosed to you by the broker or other financial intermediary. Please contact your broker or other financial intermediary for further detail. Because the Funds are not parties to any such commission arrangement between you and your broker or financial intermediary, any purchases and redemptions of a Fund' shares will be made at the applicable net asset value (before imposition of the commission). Any such commissions charged by a broker or financial intermediary are not reflected in the

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fees and expenses listed in the "Fund Fees and Expenses" section of the Summary Section for each Fund nor are they reflected in the performance information shown in the prospectus for the Funds because they are not charged by the Funds.

TAX STATUS, DIVIDENDS AND DISTRIBUTIONS

The Funds intend to qualify as regulated investment companies for federal income tax purposes and, as such, they will not be subject to federal income tax on their taxable income and gains that they distribute to their shareholders. Under ordinary circumstances, the Funds intend to distribute their income and gains in such a way that they will not be subject to a federal excise tax on certain undistributed amounts. However, no assurance can be given that the Funds will not be subject to the excise tax.

Arbitrage Fund and Water Island Event-Driven Fund intend to distribute substantially all of their net investment income and net realized capital gains after May 31, the end of each fiscal year, and no later than December 31 of each year. Water Island Credit Opportunities Fund intends to declare dividends based on its investment income daily (and distribute such dividends monthly), and distribute substantially all of its net realized capital gains in December. Distributions will be reinvested in shares of the applicable Fund unless you elect to receive cash. Distributions from net investment income (including any excess of net short-term capital gains over net long-term capital losses) are generally taxable to investors as ordinary income (although a portion of such distributions may be taxable to investors at the lower rate applicable to qualified dividend income), while distributions of capital gains (the excess of net long-term capital gains over net short-term capital losses) are taxable as long-term capital gains, regardless of your holding period of Fund shares. Arbitrage Fund and Water Island-Event Driven Fund expect that, as a result of their investment objectives and strategies, their distributions will consist primarily of short-term capital gains, which are taxable as ordinary income. Certain dividends or distributions declared in October, November or December will be taxed to shareholders as if received in December if they are paid during the following January. Each year the Funds will inform you of the amount and type of your distributions. IRAs and other qualified retirement plans are exempt from federal income taxation unless they incur debt to finance the acquisition of Fund shares.

Redemptions of shares of the Funds are taxable events on which you may realize a gain or loss.

U.S. individuals, trusts, and estates with income above certain thresholds are subject to the Medicare contribution tax at a rate of 3.8% on their net investment income, which includes interest, dividends, and capital gains.

Federal law requires the Funds (or their administrative agent) to report to the IRS and furnish to Fund shareholders the cost basis information and holding period for Fund shares purchased on or after January 1, 2012 and redeemed on or after that date. The Funds will permit Fund shareholders to elect from among several IRS-accepted cost basis methods, including average cost. In the absence of an election, the Funds will use average cost as the default cost basis method. The cost basis method a shareholder elects may not be changed with respect to a redemption of shares after the settlement date of the redemption. Fund shareholders should consult with their tax advisors to determine the best IRS-accepted cost basis method for their tax situation and to obtain more information about how the new cost basis reporting rules apply to them.

The Funds require you to certify that your Social Security number or taxpayer identification number is correct and that you are not subject to backup withholding for failing to report income to the IRS. If you are subject to backup withholding or you did not certify your taxpayer identification number, the IRS requires the Funds to withhold 24% of any distribution and redemption proceeds. The Funds reserve the right to reject your purchase order if you have not provided a certified Social Security or taxpayer identification number.

The tax consequences described in this section apply whether distributions are taken in cash or reinvested in additional shares. In addition to federal taxes, you may be subject to state and local taxes on distributions. This summary is not intended to be and should not be construed to be legal or tax advice. You should consult your own tax advisors to determine the tax consequences of owning Fund shares.

Foreign Taxes

The Funds may be subject to foreign withholding taxes with respect to income from foreign securities. The Funds do not expect to be able to "pass through" those taxes to the shareholders but will deduct such amounts in determining how much the Funds are required to distribute to their shareholders.

U.S. Taxation of Foreign Shareholders

Nonresident aliens, foreign corporations and other non-U.S. investors in the Funds will be subject to a 30% withholding tax on dividend distributions (other than capital gain dividends, unless the shareholder is entitled to a lower rate pursuant to an applicable tax treaty). A foreign shareholder must provide an applicable Form W-8 certifying its foreign status and the applicability of any treaty. Foreign investors are generally not subject to U.S. income tax or distributions of capital gains and capital gains recognized on the sale, exchange, or redemption of shares unless they are present in the U.S. for 183 days or more in a taxable year, or such gains are effectively connected with a U.S. trade or business. Certain interest-related dividends and short-term capital gain dividends are also exempt from withholding if they are separately reported by a Fund. Under the Foreign Account Tax Compliance Act ("FATCA"), the Funds are required to withhold tax at the rate of 30% on payments to certain foreign entities that do not comply with information reporting or certification requirements under FATCA.

All foreign investors should consult their tax advisors about the tax consequences of investing in a Fund.

ADDITIONAL INFORMATION

The Funds enter into contractual arrangements with various parties, which may include, among others, the Funds' investment adviser, custodian, distributor, and transfer agent, who provide services to the Funds. Shareholders are not parties to any such contractual arrangements and are not intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them against the service providers or to seek any remedy under them against the service providers, either directly or on behalf of the Funds.

This prospectus provides information concerning the Funds that you should consider in determining whether to purchase shares of the Funds. Neither this prospectus nor the SAI is intended, or should be read, to be or give rise to an agreement or contract between The Arbitrage Funds or the Funds and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

FINANCIAL HIGHLIGHTS

FINANCIAL HIGHLIGHTS

The financial highlights tables are intended to help you understand the Funds' financial performance for each fiscal period shown for Class R shares, Class I shares, Class C shares, and Class A shares, as applicable.

Please note that the financial highlights information represents financial highlights of each Fund through May 31 of each fiscal period shown below. Certain information reflects financial results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in the Funds (assuming reinvestment of all dividends and distributions). The information presented for fiscal year May 31, 2025 in the table has been derived from, and should be read in conjunction with, the financial statements audited by Cohen & Company, Ltd., whose report, along with each Fund's financial statements, are included in the Funds' Form N-CSR, which includes the Annual Financial Statements and Additional Information for the fiscal year ended May 31, 2025, which is available upon request. The information presented for fiscal years May 31, 2021, 2022, 2023 and 2024 in the table has been audited by the Funds' previous independent registered public accounting firm.

Arbitrage Fund - Class R

Selected Per Share Data and Ratios for a Share Outstanding Throughout the Periods Presented:

^(a)​ Per share amounts were calculated using average shares outstanding for the year.

^(b)​ The amount shown for a share outstanding throughout the period may not correlate with the Statements of Operations for the period due to timing of sales and redemptions of Fund shares in relation to income earned, allocation of class specific expenses and/or fluctuating market value of the investments of the Fund.

^(c)​ The Adviser has reimbursed the Fund $357 for a trading error. The impact was deemed immaterial to net realized and unrealized gain on investments and the Fund's total return, representing less than $0.005 per share.

^(d)​ Total return is a measure of the change in the value of an investment in the Fund over the years covered, which assumes any dividends or capital gains distributions are reinvested in shares of the Fund. Returns shown do not reflect the deduction of taxes a shareholder would pay on Fund distributions or the redemption of Fund shares.

^(e)​ Dividend expense totaled 0.02%, 0.08%, 0.01%, 0.01% and 0.00% of average net assets for the years ended May 31, 2025, 2024, 2023, 2022 and 2021, respectively. Interest rebate expense and line of credit interest expense totaled 0.01%, 0.00%, 0.00%, 0.05% and 0.11% of average net assets for the years ended May 31, 2025, 2024, 2023, 2022 and 2021, respectively.

^(f)​ Excluding dividend and interest expenses, the Fund's net expenses after advisory fees waived and expenses reimbursed would have been 1.52%, 1.48%, 1.44%, 1.43% and 1.47% of average net assets for the years ended May 31, 2025, 2024, 2023, 2022 and 2021, respectively.

FINANCIAL HIGHLIGHTS

Arbitrage Fund - Class I

Selected Per Share Data and Ratios for a Share Outstanding Throughout the Periods Presented: