Summary Prospectus by Investment Company (Form 497K)

FPA Global Equity ETF
FPAG

Summary Prospectus January 31, 2026

Before you invest, you may want to review the Fund's prospectus, which contains more information about the FPA Global Equity ETF (the "Fund") and its risks. You can find the Fund's Statutory Prospectus and Statement of Additional Information and other information about the Fund online at https://fpag.fpa.com/#resources You may also obtain this information at no cost by calling (800) 638-3060 or by sending an e-mail request to [email protected]. The Fund's Prospectus and Statement of Additional Information, both dated January 31, 2026, as each may be amended or supplemented, are incorporated by reference into this Summary Prospectus.

INVESTMENT OBJECTIVE

The FPA Global Equity ETF (the "Fund") seeks long-term growth of principal and income.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund ("Shares"). Investors may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example set forth below.

¹​ The Fund's investment adviser has contractually agreed to limit Total Annual Fund Operating Expenses (excluding any front-end or contingent deferred loads, brokerage fees and commissions, acquired fund fees and expenses, borrowing costs (such as interest and dividend expense on securities sold short), taxes, and extraordinary expenses, such as litigation expenses (which may include indemnification of Fund officers and Trustees, contractual indemnification of Fund service providers (other than the adviser))), to 0.49% of the Fund's average daily net assets through January 31, 2027. The adviser may recoup any operating expenses in excess of these limits from the Fund within three years if such recoupment can be achieved within the lesser of the foregoing expense limits and the expense limits in place at the time of recoupment. In addition, the adviser may seek reimbursement from the Fund of fees waived or payments made by the adviser to the Predecessor Fund (defined below) prior to the Predecessor Funds reorganization for a period ending three years after the date of the waiver or payment if such recoupment can be achieved within the lesser of the foregoing expense limited and the expense limits in place at the time of the recoupment. This agreement may only be terminated before its expiration date by the Board of Trustees of Investment Managers Series Trust III.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell 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 at current levels. The example reflects the Fund's contractual fee

waiver and/or expense reimbursement only for the term of the contractual fee waiver and/or expense reimbursement. This example does not include the brokerage commissions that investors may pay to buy and sell Shares. Although your actual costs may be higher or lower, your costs, based on these assumptions, 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 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. For the fiscal year ended September 30, 2025, the Fund's portfolio turnover rate was 14% of the average value of its portfolio. The Fund's portfolio turnover rate may vary from year to year as well as within a year.

PRINCIPAL INVESTMENT STRATEGIES

Although the Fund has adopted a policy to invest, under normal circumstances, at least 80% of its net assets, plus the amount of borrowings for investment purposes, in equity securities, the Fund's investment adviser, First Pacific Advisors, LP (the "Adviser"), expects to invest, under normal circumstances, at least 95% of the Fund's assets in equity securities. The Fund invests primarily in publicly traded common stocks of mid- and large-cap U.S. and non-U.S. companies, including companies in emerging market countries. The Fund defines mid- and large-cap companies to be those with market capitalizations equal to or greater than $10 billion at the time of initial purchase. These securities may be traded on major stock exchanges, regional stock exchanges, over-the-counter markets and other quotation systems. Under normal circumstances, the Fund expects to invest at least 40% of its total assets in equity securities of non-U.S. issuers (i.e., if the issuer is headquartered outside the United States, if at least 50% of its assets are outside the United States, or if at least 50% of its gross income is from non-U.S. sources). The equity securities held by the Fund may include common stocks, preferred stocks, and depositary receipts (including those paying dividends).

The Adviser manages the Fund's portfolio according to its Contrarian Value Equity Strategy, which seeks to invest in companies that currently appear out of favor or are undervalued by the stock market, including those mired in bad news according to media headlines, but have a favorable outlook for long-term total return (growth of principal and income), in the Adviser's estimation, over a period of five to ten years. The Adviser conducts deep research into the underlying financial condition and prospects of individual companies, including potential future earnings, cash flow, and dividends to shareholders. The Adviser consults with Wall Street professionals, industry consultants and the target company's customers, competitors and executives to understand the company's potential. The Adviser may, as part of its research, review current and historic SEC filings, conference call transcripts, and relevant periodicals to gain a full picture of the company.

After identifying target companies for the Fund, the Adviser selects the companies the equity securities of which are offered at a "substantial discount" to the Adviser's estimation of the company's worth or intrinsic value. In seeking a "substantial discount," the Adviser looks for genuine bargains by seeking securities it believes have a compelling economic risk/reward proposition on an absolute basis rather than relative to companies in the same industry, or a comparative index or benchmark. The Adviser may sell a security if its market price exceeds the Adviser's estimate of its intrinsic value, or if its economic risk/reward proposition is no longer compelling or less compelling than that of other investments identified by the Adviser. In seeking to achieve the Fund's investment objective, the Adviser may, at times, accept market volatility in the Fund's share price and short-term Fund underperformance.

PRINCIPAL RISKS

Risk is inherent in all investing and you could lose money by investing in the Fund. A summary description of certain principal risks of investing in the Fund is set forth below. Before you decide whether to invest in the Fund, carefully consider these risk factors associated with investing in the Fund, which may cause investors to lose money. There can be no assurance that the Fund will achieve its investment objective.

Equity Risk. Equity securities, generally common stocks, held by the Fund may experience sudden, unpredictable drops in value or long periods of decline in value. This may occur because of factors that affect the securities markets generally, such as adverse changes in economic or political conditions, the general outlook for corporate earnings, interest rates or investor sentiment. Sustained periods of market volatility, either globally or in any jurisdiction in which the Fund invests, may increase the risks associated with an investment in the Fund. Equity securities may also lose value because of factors affecting an entire industry or sector, such as increases in production costs, or factors directly related to a specific company, such as decisions made by its management. Equity securities generally have greater price volatility than debt securities.

Large-Capitalization Companies Risk. The value of investments in larger companies may not rise as much as smaller companies, or larger companies may be unable to respond quickly to competitive challenges, such as changes in technology and consumer tastes.

Mid-Capitalization Companies Risk. The earnings and prospects of mid-capitalization sized companies are more volatile than those of larger companies and they may experience higher failure rates than larger companies. Mid-capitalization companies normally have a lower trading volume than larger companies, which may tend to make their market price fall more disproportionately than larger companies in response to selling pressures and may have limited markets, product lines, or financial resources and lack management experience.

Foreign Securities Risk. The prices of foreign securities may be more volatile than the prices of securities of U.S. issuers because of economic and social conditions abroad, political developments, and changes in the regulatory environments of foreign countries. Changes in exchange rates and interest rates, and the imposition of sanctions, confiscations, trade restrictions (including tariffs) and other government restrictions by the United States and/or other governments may adversely affect the values of the Fund's foreign investments. Foreign companies are generally subject to different legal and accounting standards than U.S. companies, and foreign financial intermediaries may be subject to less supervision and regulation than U.S. financial firms.

Emerging Market Securities Risk. The Fund may invest in companies organized or doing substantial business in emerging market countries or developing countries as defined by the World Bank, International Financial Corporation, or the Morgan Stanley Capital International (MSCI) emerging market indices or other comparable indices. Many of the risks with respect to foreign investments are more pronounced for investments in issuers in developing or emerging market countries. Emerging market countries may have relatively unstable governments, weaker economies, and less-developed legal systems with fewer security holder rights. Emerging market economies may be based on only a few industries and security issuers may be more susceptible to economic weakness and more likely to default. Emerging market securities also tend to be less liquid. There may also be less reliable or publicly-available information about emerging markets due to non-uniform regulatory, auditing or financial recordkeeping standards, which could cause errors in the implementation of the Fund's investment strategy. The Fund's performance may depend on issues other than those that affect U.S. companies and may be adversely affected by different rights and remedies associated with emerging market investments, or the lack thereof, compared to those associated with U.S. companies.

Depositary Receipts Risk. Investing in depositary receipts may involve risks in addition to the risks in domestic investments, including less regulatory oversight and less publicly-available information, less stable governments and economies, and non-uniform accounting, auditing and financial reporting standards. Unsponsored depositary receipts held by the Fund are frequently under no obligation to distribute shareholder communications received from the underlying issuer, and there is less information available about unsponsored depositary receipts than sponsored depositary receipts; unsponsored depositary receipts are also not obligated to pass through voting rights to the Fund.

Preferred Stock Risk. Preferred stock represents an equity interest in a company that generally entitles the holder to receive, in preference to the holders of other stocks such as common stock, dividends and a fixed share of the proceeds resulting from a liquidation of the company. The market value of preferred stock is subject to company-specific and market risks applicable generally to equity securities and is also sensitive to changes in the company's creditworthiness, the ability of the company to make payments on the preferred stock, and changes in interest rates, typically declining in value if interest rates rise.

Market Risk. The market price of a security or instrument may decline, sometimes rapidly or unpredictably, due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic, political, or geo-political conditions throughout the world, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. The market value of a security or instrument also may decline because of factors that affect a particular industry or industries, such as tariffs, labor shortages or increased production costs and competitive conditions within an industry. In addition, local, regional or global events such as war, acts of terrorism, international conflicts, trade disputes, supply chain disruptions, cybersecurity events, the spread of infectious illness or other public health issues, natural disasters or climate events, or other events could have a significant impact on a security or instrument. The increasing interconnectivity between global economies and financial markets increases the likelihood that events or conditions in one region or financial market may adversely impact issuers in a different country, region or financial market.

ETF Structure Risks. The Fund is an ETF, and, as a result of an ETF's structure, it is exposed to the following risks:

• Authorized Participant Concentration Risk. Only an authorized participant may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that act as authorized participants on an agency basis (i.e., on behalf of other market participants). To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders with respect to the Fund and no other authorized participant is able to step forward to process creation or redemption orders, Shares may trade at a discount to the Fund's net asset value ("NAV") and possibly face delisting.

• Cash Transaction Risk. To the extent the Fund sells portfolio securities to meet some or all of a redemption request with cash, the Fund may incur taxable gains or losses that it might not have incurred had it made redemptions entirely in-kind. As a result, the Fund may pay out higher annual capital gain distributions than if the in-kind redemption process was used.

• Market Maker Risk. If the Fund has lower average daily trading volumes, it may rely on a small number of third-party market makers to provide a market for the purchase and sale of Fund Shares. Any trading halt or other problem relating to the trading activity of these market makers could result in a dramatic change in the spread between the Fund's NAV and the price at which the Fund Shares are trading on the Exchange, which could result in a decrease in value of the Fund Shares. In addition, decisions by market makers or authorized participants to reduce their role or step away from these activities in times of market stress could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying values of the Fund's portfolio securities and the Fund's market price. This reduced effectiveness could result in Fund Shares trading at a discount to NAV and also in greater than normal intra-day bid-ask spreads for Fund Shares.

• Fluctuation of NAV Risk. As with all ETFs, Shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of Shares will approximate the Fund's NAV, there may be times when the market price of Shares is more than the NAV intra-day (premium) or less than the NAV intra-day (discount). Differences in market price and NAV may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for Shares will be closely related to, but not identical to, the same forces influencing the prices of the holdings of the Fund trading individually or in the aggregate at any point in time. These differences can be especially pronounced during times of market volatility or stress. During these periods, the demand for Fund Shares may decrease considerably and cause the market price of Fund Shares to deviate significantly from the Fund's NAV.

• Market Price Could Vary From NAV Due to Foreign Holdings. The Fund may hold shares of non-U.S. securities traded in local markets that close at a different time than the Exchange. To the extent underlying securities held by the Fund trade on foreign exchanges that are closed when the Exchange is open, there may be deviations between the current price of an underlying security and the last quoted price for the underlying security on the closed foreign market. This could lead to differences between the market price of the Fund's Shares and the underlying value of the Fund Shares. These differences can be magnified during times of significant market activity.

• Trading Issues Risk. Although the Fund Shares are listed for trading on the Exchange, there can be no assurance that an active trading market for such Fund Shares will develop or be maintained. Trading in Fund Shares on the Exchange may be halted due to market conditions or for reasons that, in the view of the Exchange, make trading in Fund Shares inadvisable. In addition, trading in Fund Shares on the Exchange is subject to trading halts caused by extraordinary market volatility pursuant to the Exchange "circuit breaker" rules. Market makers are under no obligation to make a market in the Fund Shares, and authorized participants are not obligated to submit purchase or redemption orders for Creation Units. There can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund will continue to be met or will remain unchanged. Initially, due to the small asset size of the Fund, it may have difficulty maintaining its listings on the Exchange.

• Costs of Buying or Selling Shares. Investors buying or selling Shares in the secondary market will pay brokerage commissions or other charges imposed by brokers, as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Shares. In addition, secondary market investors will also incur the cost of the difference between the price at which an investor is willing to buy Shares (the "bid" price) and the price at which an investor is willing to sell Shares (the "ask" price). This difference in bid and ask prices is often referred to as the "spread" or "bid-ask spread." The bid-ask spread varies over time for Shares based on trading volume and market liquidity, and the spread is generally lower if Shares have more trading volume and market liquidity and higher if Shares have little trading volume and market liquidity. Further, a relatively small investor base in the Fund, asset swings in the Fund, and/or increased market volatility may cause increased bid-ask spreads. Due to the costs of buying or selling Shares, including bid-ask spreads, frequent trading of Shares may significantly reduce investment results and an investment in Shares may not be advisable for investors who anticipate regularly making small investments.

• Shares are Not Individually Redeemable. Shares are only redeemable by the Fund at NAV if they are tendered in Creation Units. Only APs may engage in such creation and redemption transactions directly with the Fund. Individual Shares may be sold on a stock exchange at their current market prices, which may be less, more, or equal to their NAV.

Active Management Risk. The Fund is actively managed by its portfolio managers. There is a risk that an investment technique used by the Fund's portfolio managers may fail to produce the intended result. The Adviser's judgments about the growth, value or potential appreciation of an investment may prove to be incorrect or fail to have the intended results, which could adversely impact the Fund's performance and cause it to underperform relative to other funds with similar investment goals or not to achieve its investment goal.

Issuer-Specific Changes. The value of an individual security can be more volatile than the market as a whole and can perform differently than the value of the market as a whole.

Headline Risk. The Fund may invest in companies that are at the center of controversy because of negative media attention regarding its operations, long-term prospects, or management which may cause short-term underperformance.

Non-Diversified Risk. The Fund intends to invest in a variety of securities and instruments, but the Fund is considered to be non-diversified, which means that it may invest more of its assets in the securities of a single issuer or a smaller number of issuers than if it were a diversified fund. As a result, the Fund may be more exposed to the risks associated with and developments affecting an individual issuer or a smaller number of issuers than a fund that invests more widely. This may increase the Fund's volatility and cause the performance of a relatively smaller number of issuers to have a greater impact on the Fund's performance.

Value Investing Risk. The Adviser's assessment of a stock's intrinsic value may never be fully recognized or realized by the market, and a stock judged to be undervalued or overvalued may actually be appropriately priced or its price may decline.

Volatility Risk. The Fund may have investments that appreciate or decrease significantly in value over short periods of time. This may cause the Fund's NAV per share to experience significant increases or declines in value over short periods of time.

Recent Market Events. Periods of market volatility may occur in response to market events, public health emergencies, natural disasters or climate events, and other economic, political, and global macro factors. U.S. and international markets have recently experienced, and may continue to experience, periods of significant volatility due to various factors, including uncertainty regarding inflation and central banks' interest rate changes, the possibility of a national or global recession, trade tensions and tariffs, and political and geopolitical events. In addition, wars, or threats of war and aggression, such as Russia's invasion of Ukraine and the conflicts among nations and militant groups in the Middle East, have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on the U.S. and world economies and markets generally, each of which may negatively impact the Fund's investments. Additionally, since the change in the U.S. presidential administration in 2025, the administration has pursued an aggressive foreign policy agenda, including actual or potential imposition of tariffs, which may have consequences on the United States' relations with foreign countries, the economy, and markets generally. These and other similar events could be prolonged and could adversely affect the value and liquidity of the Fund's investments, impair the Fund's ability to satisfy redemption requests, and negatively impact the Fund's performance.

Cybersecurity Risk. Cybersecurity incidents may allow an unauthorized party to gain access to Fund assets, customer data (including private shareholder information), or proprietary information, or cause the Fund, the Adviser and/or other service providers (including custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or loss of operational functionality. In an extreme case, a shareholder's ability to exchange or redeem Fund shares may be affected. The use of artificial intelligence and machine learning could exacerbate these risks. Issuers of securities in which the Fund invests are also subject to cybersecurity risks, and the value of those securities could decline if the issuers experience cybersecurity incidents.

PERFORMANCE

The Fund commenced operations and acquired the assets and liabilities of the FPA Global Equity ETF, a series of Northern Lights Fund Trust III (the "Predecessor Fund"), resulting from a reorganization of the Predecessor Fund with and into the Fund, on April 26, 2024. As a result of the acquisition, the Fund is the accounting successor of the Predecessor Fund. Performance results shown in the bar chart and the performance table below for the periods through April 26, 2024, reflect the performance of the Predecessor Fund.

The bar chart and Average Annual Total Returns table below provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on NAV compared with those of the MSCI All Country World Index ("ACWI") (Net), a broad-based securities market index. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The Fund's performance information is accessible on the Fund's website at https://fpag.fpa.com or by calling (800) 982-4372.

Calendar-Year Total Return (before taxes)
For each calendar year at NAV

Best and Worst Quarter Returns (for the period reflected in the bar chart above)

Highest Calendar Quarter Return at NAV 12.54% Quarter ended 12/31/22

Lowest Calendar Quarter Return at NAV (15.60)% Quarter ended 6/30/22

¹​ After-tax returns were 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 Shares of the Fund through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

²​ The MSCI ACWI (Net) is a stock index designed to track broad global equity-market performance. Maintained by Morgan Stanley Capital International (MSCI), the index comprises the stocks of nearly 3,000 companies from 23 developed countries and 25 emerging markets. Investors cannot invest directly in an index.

MANAGEMENT

Investment Adviser

First Pacific Advisors, LP serves as the Fund's investment adviser.

PORTFOLIO MANAGERS

Mark Landecker, CFA, Partner of the Adviser, and Brian A. Selmo, CFA, Partner of the Adviser, serve as portfolio managers of the Fund. Each portfolio manager is jointly and primarily responsible for the day-to-day management of the Fund and has served as portfolio manager of the Predecessor Fund since its inception in December 2021, and for the Fund since the reorganization of the Predecessor Fund on April 26, 2024.

PURCHASE AND SALE OF SHARES

The Fund issues and redeems Shares on a continuous basis, at NAV, only in large blocks of shares called "Creation Units." Each Creation Unit is 25,000 Shares. Except when aggregated in Creation Units, the Shares are not redeemable securities of the Fund.

Individual Shares of the Fund may only be purchased and sold on the secondary market through a broker-dealer. Since Shares of the Fund trade on securities exchanges in the secondary market at their market price rather than their NAV, the Fund's Shares may trade at a price greater than (premium) or less than (discount) the Fund's NAV. An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase Shares of the Fund (bid) and the lowest price a seller is willing to accept for Shares of the Fund (ask) when buying or selling Shares in the secondary market (the "bid-ask spread"). Recent information, including the Fund's NAV, market price, premiums and discounts, and bid-ask spreads, is available online at https://fpag.fpa.com.

TAX INFORMATION

The Fund's distributions will generally be taxable as ordinary income, returns of capital or capital gains. A sale of Shares may result in capital gain or loss.

PAYMENTS TO BROKER-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase Shares through a broker-dealer or other financial intermediary (such as a bank), the Adviser and Distribution Services, LLC, the Fund's distributor, may pay the intermediary for the sale of 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.