Summary Prospectus by Investment Company (Form 497K)

OAKGSUMPRO

November 11, 2025

Summary Prospectus

Oakmark Global Large Cap ETF

OAKG

Before you invest, you may want to review the Fund's prospectus and statement of additional information, which contain more information about the Fund and its risks. You can find the Fund's prospectus and other information about the Fund online at oakmark.com/etfs/oakg. You can also get this information at no cost by calling 800-458-7452 or by sending an email request to [email protected]. You can also get this information from your financial intermediary or any financial intermediary authorized to sell the Fund's shares. The Fund's prospectus and statement of additional information, dated November 11, 2025, and as each may be further supplemented or amended, are incorporated by reference into this Summary Prospectus.

Investment objective

Oakmark Global Large Cap ETF seeks long-term capital appreciation.

Fees and expenses of the Fund

Below are the fees and expenses that you would pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below.

Shareholder Fees (fees paid directly from your investment)

None.

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

¹​ Based on estimated amounts for the current fiscal year.

²​ Harris Associates, L.P. (the "Adviser") has contractually undertaken to waive its management fee by 0.05% of the Fund's average daily net assets. The undertaking lasts until January 27, 2027 and may not be terminated during its term without the consent of the Board of Trustees.

Example. The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 for the time periods indicated and then redeem 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 were those reflected in the table, inclusive of any fee waivers and/or expense reimbursements.

Although your actual returns and expenses may be higher or lower, based on these assumptions your expenses 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. As of the date of this prospectus, the Fund had not yet commenced operations and had no portfolio turnover information to report.

Principal investment strategy

The Fund invests primarily in a diversified portfolio of equity securities of U.S. and non-U.S. large capitalization companies. Under normal circumstances, the Fund will invest at least 80% of its net assets (plus borrowings made for investment purposes) in securities of large capitalization companies. A large capitalization company is one whose market capitalization is not smaller than the smallest market capitalization of a company in the MSCI World Large Cap Index. As of September 30, 2025, the smallest market capitalization in the MSCI World Large Cap Index was $1.743 billion.

Under normal market conditions, the Fund will not invest more than 30% of its total assets (measured at time of investment) in companies located in a single country (other than the U.S.) and will not invest more than 25% of its assets in one industry. Typically, the Fund invests between 25-65% of its total assets in securities of U.S. companies and between 25-65% of its total assets in securities of non-U.S. companies. In determining whether an issuer is a U.S. or non-U.S. company, the Fund considers various factors including its country of domicile, the primary stock exchange on which it trades, the location from which the majority of its revenue comes, and its reporting currency. There are no geographic limits on the Fund's non-U.S. investments, and the Fund may invest in securities of companies located in developed or emerging markets. The Fund considers emerging markets to be markets located in countries classified as emerging or frontier markets by MSCI, and are generally located in the AsiaPacific region, Eastern Europe, the Middle East, Central and South America, and Africa.

The Fund uses a value investment philosophy in selecting equity securities. This value investment philosophy is based upon the belief that, over time, a company's stock price converges with the Adviser's estimate of the company's intrinsic value. By "intrinsic value," the Adviser means its estimate of the price a knowledgeable buyer would pay to acquire the entire business. The Adviser believes that investing in securities priced significantly below what it believes is a company's intrinsic value

presents the best opportunity to achieve the Fund's investment objective. A company trading below its estimated intrinsic value is sometimes referred to as trading at a discount.

The Adviser uses this value investment philosophy to identify companies that have discounted stock prices compared to what the Adviser believes are the companies' intrinsic values. In assessing such companies, the Adviser looks for a number of attractive attributes which could include: (1) free cash flows; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management alignment with shareholders.

Key Tenets of the Oakmark Value Investment Philosophy:
1. Buy businesses that are trading at a significant discount to the Adviser's estimate of the company's intrinsic value. At the time the Adviser buys a company, the Adviser wants the company's stock to be inexpensive relative to what it believes the entire business is worth.
2. Invest with companies expected to grow shareholder value over time. Value investors can sometimes fall into the trap of buying a stock that is inexpensive for a reason-because the company just does not grow. The Adviser looks for businesses that are expected to achieve a combination of dividend yield and per-share growth in business value that is above-average.
3. Invest with management teams that think and act as owners. The Adviser seeks out companies with management teams that understand the dynamics of per share value growth and are focused on achieving such growth. Stock ownership and incentives that align managements' interests with those of shareholders are key components of this analysis.

In making its investment decisions, the Adviser uses a "bottom-up" approach focused on individual companies, rather than focusing on specific economic factors or specific industries. To facilitate its selection of investments that meet the criteria described above, the Adviser uses independent, in-house research to analyze each company. As part of this selection process, the Adviser's analysts typically visit companies and conduct other research on the companies and their industries.

Once the Adviser identifies a stock that it believes is selling at a significant discount to the Adviser's estimated intrinsic value and that the company possesses the other key tenets of the investment philosophy, the Adviser may consider buying that stock for the Fund. The Adviser usually sells a stock when the price approaches its estimated intrinsic value. This means the Adviser sets specific "buy" and "sell" targets for each stock the Fund holds. The Adviser monitors each portfolio holding and adjusts these price targets as warranted to reflect changes in a company's fundamentals.

The Adviser believes that holding a relatively small number of issuers allows its "best ideas" to have a meaningful impact on the Fund's performance. Therefore, the Fund's portfolio typically holds 30-60 issuers rather than hundreds, and as a result, a higher percentage of the Fund's total assets may at times be invested in a particular region, sector or industry.

The Fund will not change its policy to invest at least 80% of its net assets (plus borrowings made for investment purposes) in securities of large capitalization companies without providing shareholders at least 60 days' advance notice.

Principal investment risks

As an investor in the Fund, you should have a long-term perspective and be able to tolerate potentially wide fluctuations in the value of your Fund shares. Your investment in the Fund is subject to risks, including the possibility that the value of the Fund's portfolio holdings may fluctuate in response to events specific to the companies in which the Fund invests, as well as economic, political or social events in the United States or abroad and the Adviser's evaluation of those events, and the success of the Adviser in implementing the Fund's investment strategy. As a result, when you redeem your Fund shares, they may be worth more or less than you paid for them.

Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. You may lose money by investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time.

Although the Fund makes every effort to achieve its investment objective, it cannot guarantee it will attain that investment objective. The following principal investment risks can significantly affect the Fund's performance:

Market Risk. The Fund is subject to market risk-the risk that securities markets and individual securities will increase or decrease in value. Market risk applies to every market and every security. Security prices may fluctuate widely over short or extended periods in response to adverse issuer, political, geopolitical (including wars or acts of terrorism), regulatory, market, economic, sanctions, global health crises or pandemics, environmental, or other developments that may cause broad changes in market value, stability, and public perceptions concerning these developments, and adverse investor sentiment. In addition, securities markets tend to move in cycles. If there is a general decline in the securities markets, it is possible your investment may lose value regardless of the individual results of the companies in which the Fund invests. The magnitude of up and down price or market fluctuations over time is sometimes referred to as "volatility," which, at times, can be significant. In addition, different asset classes and geographic markets may experience periods of significant correlation with each other. As a result of this correlation, the securities and markets in which the Fund invests may experience volatility due to market, economic, political or social events, such as global health crises or pandemics, and conditions that may not readily appear to directly relate to such securities, the securities' issuer or the markets in which they trade. In addition, some companies may have substantial foreign operations or holdings and may involve additional risks relating to those markets, including but not limited to political, economic, regulatory, or other conditions in foreign countries, as well as currency exchange rates.

Focused Portfolio Risk. The Fund's portfolio tends to be invested in a relatively small number of issuers. As a result, the appreciation or depreciation of any one issuer held by the Fund will have a greater impact on the Fund's net asset value than it would if the Fund invested in a larger number of issuers. Although that strategy has the potential to generate attractive returns over time, it also increases the Fund's volatility and may lead to greater losses.

Non-U.S. Securities Risk. Investments in securities issued by entities based outside the United States may involve risks relating to political, social and economic developments abroad, as well as risks resulting from the differences between the regulations to which U.S. and non-U.S. issuers and markets are subject. These risks may be difficult to predict and may result in the Fund experiencing rapid and extreme value changes due to currency controls; trade barriers, sanctions and other protectionist trade

policies (including those of the U.S.); different accounting, auditing, financial reporting, and legal standards and practices; political and diplomatic changes and developments; expropriation; changes in tax policy; a lack of available public information regarding non-U.S. issuers; greater market volatility; a lack of sufficient market liquidity; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. These risks may be heightened in connection with investments in issuers located in developing and emerging countries, and in issuers in more developed countries that conduct substantial business in such developing and emerging countries. Fluctuations in the exchange rates between currencies may negatively affect an investment in non-U.S. securities. Different markets or regions may react to developments differently than one another or the U.S. Investments in securities issued by entities domiciled in the U.S. also may be subject to many of these risks. The Fund may hedge its exposure to foreign currencies. Although hedging may be used to protect the Fund from adverse currency movements, the use of such hedges may reduce or eliminate the potentially positive effect of currency revaluations on the Fund's total return, and there is no guarantee that the Fund's hedging strategy will be successful.

Liquidity Risk. From time to time, the trading market generally or for a particular investment or instrument in which the Fund is invested, including securities of issuers located outside the United States, may become less liquid or even illiquid. Illiquid investments can be more difficult to purchase or sell at an advantageous price or time, and there is a greater risk that they may not be sold for the price at which the Fund is carrying them. This risk may be heightened with investments in issuers located in developing and emerging countries. Market closures due to holidays or other factors may render a security or group of securities (e.g., securities tied to a particular country or geographic region) illiquid for a period of time. Certain investments that were liquid when a Fund purchased them may become illiquid, sometimes abruptly. The inability to sell an investment can adversely affect the Fund's value or prevent the Fund from being able to take advantage of other investment opportunities.

Emerging Markets Risk. The risks of investing in non-U.S. securities may be heightened for securities of issuers located in emerging market countries. Emerging market countries tend to have economic structures that are less diverse and mature, and political systems that are less stable, than those of developed countries. Emerging market countries may also have less developed legal and accounting systems. In addition to all of the risks of investing in non-U.S. securities, emerging markets are more susceptible to governmental interference, local taxes being imposed on foreign investments, restrictions on gaining access to sales proceeds, and less liquid and efficient trading markets.

Equity Securities Risk. Equity securities may be subject to greater fluctuations in market value than other asset classes as a result of such factors as a company's business performance, investor perceptions, stock market trends and general economic conditions. The rights of equity stockholders are subordinate to all other claims on a company's assets including, debt holders and preferred stockholders; therefore, the Fund could lose money if a company in which it invests becomes financially distressed.

Region, Sector or Industry Risk. If the Fund has invested a higher percentage of its total assets in a particular region, sector or industry, changes affecting that region, sector or industry, or the perception of that region, sector or industry, may have a significant impact on the performance of the Fund's overall

portfolio. Individual regions, sectors or industries may be more volatile, and may perform differently, than the broader market.

Large Capitalization Securities Risk. Investing primarily in issuers in one market capitalization category (large) carries the risk that due to current market conditions, that category may be out of favor with investors. Larger, more established companies may be unable to respond quickly to new competitive challenges or opportunities or attain the high growth rate of successful smaller companies.

Large Shareholder Risk. Certain large shareholders, including Authorized Participants, may from time to time own a substantial amount of the Fund's shares. There is no requirement that these shareholders maintain their investment in the Fund. There is a risk that such large shareholders or that the Fund's shareholders generally may redeem all or a substantial portion of their investments in the Fund in a short period of time, which could have a significant negative impact on the Fund's NAV, liquidity, and brokerage costs. Large redemptions could also result in tax consequences to shareholders and impact the Fund's ability to implement its investment strategy.

Value Style Risk. Investing in "value" stocks presents the risk that the stocks may never reach what the Adviser believes are their full market values, either because the market fails to recognize what the Adviser considers to be the companies' intrinsic values or because the Adviser misjudged those values. In addition, value stocks may fall out of favor with investors and underperform other investments during given periods.

ETF Risk. As an exchange-traded fund ("ETF"), the Fund is subject to the following risks:

Authorized Participants Concentration Risk. The Fund has a limited number of financial institutions that may act as Authorized Participants. To the extent they exit the business or are otherwise unable to proceed in creation and redemption transactions with the Fund and no other Authorized Participant is able to step forward to create or redeem, shares of the Fund may be more likely to trade at a premium or discount to net asset value ("NAV") and possibly face trading halts or delisting.

Cash Transactions Risk. The Fund may effect its creations and redemptions in cash or partially in cash. As a result, an investment in the Fund may be less tax-efficient than an investment in other ETFs that effect their creations and redemptions primarily on an in-kind basis.

Premium/Discount Risk. There may be times when the market price of the Fund's shares is more than the NAV intra-day (at a premium) or less than the NAV intra-day (at a discount). As a result, shareholders of the Fund may pay more than NAV when purchasing shares and receive less than NAV when selling Fund shares. This risk is heightened in times of market volatility or periods of steep market declines. In such market conditions, market or stop loss orders to sell Fund shares may be executed at prices well below NAV.

Secondary Market Trading Risk. Investors buying or selling shares in the secondary market will normally pay brokerage commissions, which are often a fixed amount and may be a significant proportional cost for investors buying or selling relatively small amounts of shares. Secondary market trading is subject to bid-ask spreads, which is the difference between the highest price a buyer is willing to pay to purchase shares of a fund (bid) and the lowest price a seller is willing to accept for shares (ask) when buying or selling shares in the secondary market, and trading in Fund shares may be halted by the Exchange because of market conditions or other reasons. If a trading halt occurs, a shareholder may temporarily be unable to purchase or sell shares of the Fund.

The bid-ask spread, which varies over time, is generally narrower if the Fund has more trading volume and market liquidity and wider if the Fund has less trading volume and market liquidity. In addition, the bid-ask spread can be affected by the liquidity of the Fund's underlying investments and can widen if the Fund's underlying investments become less liquid or illiquid. In addition, although the Fund's shares are listed on the Exchange, there can be no assurance that an active trading market for shares will develop or be maintained or that the Fund's shares will continue to be listed.

New Fund Risk. The Fund is a new fund, with a limited operating history, which may result in additional risks for investors in the Fund. There can be no assurance that the Fund will grow to an economically viable size, in which case the Fund may cease operations. In such an event, investors may be required to liquidate or transfer their investments at an inopportune time.

Performance information

Performance history will be included for the Fund after the Fund has been in operation for one calendar year. Until that time, call 800-458-7452 or go to oakmark.com/etfs/oakg for performance information. Past performance (before and after taxes) is not a prediction of future results.

Investment adviser

Harris Associates L.P. is the Fund's investment adviser.

Portfolio managers

Anthony P. Coniaris, CFA, David G. Herro, CFA, M. Colin Hudson, CFA, Eric Liu, CFA, and John A. Sitarz, CFA, CPA manage the Fund's portfolio. Mr. Coniaris is Chairman, Co-Chief Investment Officer of International Equities, and a portfolio manager of the Adviser. He joined the Adviser in 1999 and has managed the Fund since inception. Mr. Herro is Deputy Chairman, Co-Chief Investment Officer of International Equities, a portfolio manager, and analyst of the Adviser. He joined the Adviser in 1992 and has managed the Fund since inception. Mr. Hudson is a portfolio manager and analyst of the Adviser. He joined the Adviser in 2005 and has managed the Fund since inception. Mr. Liu is a vice president, portfolio manager and analyst of the Adviser. He joined the Adviser in 2009 and has managed the Fund since inception. Mr. Sitarz is a portfolio manager and analyst of the Adviser. He joined the Adviser in 2013 and has managed the Fund since inception.

Purchase and sale of fund shares

The Fund issues shares to, and redeems shares from, certain institutional investors known as Authorized Participants (typically market makers or other broker-dealers who have entered into contractual arrangements with the Fund's distributor) only in large blocks of Fund shares known as "Creation Units." Creation Unit transactions are generally conducted in exchange for the deposit or delivery of a portfolio of in-kind securities designated by the Fund and a specified amount of cash.

Individual Fund shares may only be purchased and sold in the secondary market, such as a national securities exchange, through a broker or dealer at a market price. These transactions do not involve the Fund. Because Fund shares trade at market prices rather than at NAV, Fund shares may trade at a price greater than NAV (premium) or less than NAV (discount). When buying or selling shares in the secondary market, you 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) (the "bid-ask spread"). Most investors will incur customary brokerage commissions and charges when buying and selling shares of the Fund through a broker or dealer. However, because the Fund is new, it does not currently have sufficient trading history to report trading information and related costs. When available, recent information regarding the Fund's NAV, market price, premiums and discounts, and bid-ask spreads will be available at oakmark.com/etfs/oakg.

Tax information

The Fund's distributions may be taxable to you as ordinary income and/or capital gains, unless you are invested through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account.

Payments to broker-dealers and other financial intermediaries

If you purchase shares of the Fund through an intermediary, the Adviser or its affiliates may pay the intermediary for the sale of Fund shares and/or related services. These payments may create a conflict of interest by influencing the intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your intermediary's website for more information.