Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. The Fund’s Prospectus and Statement of Additional Information, both dated April 30, 2024, as may be subsequently amended, are incorporated by reference into this Summary Prospectus. You can find the Fund’s Prospectus, reports to shareholders, when available, and other information about the Fund online (https://www.driehaus.com/fund-resources). You can also get this information at no cost by calling 1-800-560-6111, by sending an email request to mutualfunds@driehaus.com, or by asking any financial advisor, bank, or broker-dealer who offers shares of the Fund.

Investment Objective

Driehaus International Developed Equity Fund seeks to maximize capital appreciation.

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. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

Expense 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. The Example assumes that you invest $10,000 in the Fund 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 remain the same. The expense reimbursement shown in the Annual Fund Operating Expenses table is reflected for each of the first three years in the Example. 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. Portfolio turnover information is not included since the Fund has not commenced operations as of the date of this Prospectus.

Principal Investment Strategy

Under normal market conditions, the Fund invests at least 80% of its net assets (plus the amount of borrowings for investment purposes) in equity securities issued by non-U.S. developed market companies of all market-capitalizations.

The Fund will invest in equity securities, including common stock and depositary receipts, of companies located in non-U.S. developed market countries. The Fund’s investment adviser considers a company to be a developed market company if such company is organized under the laws of, if its principal offices are in, its securities are principally traded in, or if the company derives at least 50% of its revenues or net profits from, or has at least 50% of its assets in, a developed market country defined by the MSCI World ex USA Growth Index. From time to time, the Fund may invest a significant portion of its assets in the securities of companies domiciled in one or a few countries or regions. The Fund may invest in companies of any size, but its focus will typically be in large-capitalization companies. The Fund may participate in initial public offerings (“IPOs”) and in securities offerings that are not registered in the United States. While the Fund will invest primarily in the equity securities of non-U.S. developed market countries, the Fund may also from time to time invest up to a maximum of 20% of its assets in the equity securities of U.S. companies and/or non-developed market securities.

In managing the Fund, the investment adviser uses an investment approach that integrates top-down (focusing on the economy and market trends) analysis of the overall economy and bottom-up (focusing on individual stocks) analysis of individual securities. From a top-down perspective, the investment adviser looks at the relative value of securities to identify assets to include in the Fund’s portfolio. Bottom-up analysis involves evaluating fundamental factors, including a company’s business model, the competitive landscape, upcoming product introductions and recent and projected financial metrics in order to identify companies with more attractive earnings growth on a prospective basis. The investment adviser’s decision to buy or sell a security is also based on the evaluation of technical or market factors, including price and volume trends, relative strength and institutional interest.

Principal Risks

All investments, including those in mutual funds, have risks. No investment is suitable for all investors. The Fund is intended for long-term investors who can accept the risks involved in investing in foreign securities. Of course, there can be no assurance that the Fund will achieve its objective. You may lose money by investing in the Fund. Below are the main risks of investing in the Fund:

Market Risk. The Fund is subject to market risk, which is the possibility that stock prices overall will decline over short or long periods. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. These fluctuations are expected to have a substantial influence on the value of the Fund’s shares. Due to the uncertainty caused by war, acts of terrorism, geopolitical conflict, public health issues, recessions, economic cycles, monetary and fiscal policy, company earnings, global pandemics and other risks, global markets may experience increased volatility which could adversely affect the performance of the Fund’s investments.

Foreign Securities and Currencies Risk. The following risks may be associated with investments in foreign securities: less liquidity; greater volatility; political instability; restrictions on foreign investment and repatriation of capital; less complete and reliable information about foreign companies; reduced government supervision of some foreign securities markets, U.S. and foreign government actions, such as the imposition of tariffs, economic and trade sanctions or embargoes; lower responsiveness of foreign management to shareholder concerns; economic issues or developments in foreign countries; fluctuation in exchange rates of foreign currencies and risks of devaluation; and imposition of foreign withholding and

other taxes. To the extent portfolio securities are issued by foreign issuers or denominated in foreign currencies, the Fund’s investment performance is affected by the strength or weakness of the U.S. dollar against these currencies. Generally, an increase in the value of the U.S. dollar against a foreign currency will reduce the value of a security denominated in that foreign currency, thereby decreasing the Fund’s overall net asset value. Currency rates in foreign countries may fluctuate significantly over short or long periods of time for a number of reasons, including changes in interest rates, imposition of currency controls and economic or political developments in the U.S. or abroad.

Allocation Risk. The Fund’s overall risk level will depend on the companies, countries, regions, markets, market sectors, industries and asset classes in which the Fund is invested. Because the Fund may have significant weightings in a particular company, country, region, asset class, industry, market or market sector, the value of the Fund’s shares may be affected by events that adversely affect that company, country, region, market, industry, asset class, or market sector and may fluctuate more than that of a less focused fund.

The Fund is expected to have significant exposure to the far east region as well as to Europe and may be vulnerable to risks specific to those regions. Many countries in the far east region are subject to political risk, including corruption and regional conflict with neighboring countries. In addition, many far east countries are subject to social and labor risks associated with demands for improved political, economic, and social conditions. The far east region may be adversely affected by political, military, economic and other factors related to North Korea. Adverse economic, political or social developments in Europe, or in a particular European country, could have a negative effect on the value of the Fund’s portfolio. Many European countries are members of the European Union and, as members, such countries share a common currency and certain fiscal policies.

Equity Securities Risk. In a company liquidation, the claims of secured and unsecured creditors and owners of bonds and preferred stocks take precedence over the claims of common stock shareholders.

Manager Risk. How the Fund’s investment adviser manages the Fund will impact the Fund’s performance. The Fund may lose money if the investment adviser’s investment strategy does not achieve the Fund’s objective or the investment adviser does not implement the strategy successfully.

Growth Stock Risk. Growth stocks are typically priced higher than other stocks, in relation to earnings and other measures, because investors believe they have more growth potential. This potential may or may not be realized and, if it is not realized, may result in a loss to the Fund. Growth stock prices also tend to be more volatile than the overall market.

Depositary Receipts Risk. The Fund may invest in foreign securities in the form of depositary receipts which include American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”). Investment in Depositary Receipts does not eliminate the risks inherent in investing in the securities of foreign issuers, which include market, political, tax, currency and regulatory risk. To the extent a Fund acquires Depositary Receipts through banks which do not have a contractual relationship with the foreign issuer of the security underlying the Depositary Receipts to issue and service such unsponsored Depositary Receipts, there may be an increased possibility that the Fund would not become aware of and be able to respond to corporate actions such as stock splits or rights offerings involving the foreign issuer in a timely manner. In addition, the lack of information may result in inefficiencies in the valuation of such instruments. In the case of an unsponsored Depositary Receipt, the Fund may bear higher expenses and encounter greater difficulty in receiving shareholder communications than it would have with a sponsored Depositary Receipt. The market value of Depositary Receipts is dependent upon the market value of the underlying securities and fluctuations in the relative value of the currencies in which the Depositary Receipts and the underlying securities are quoted.

Large Capitalization Company Risk. Large capitalization companies may fall out of favor with investors based on market and economic conditions. In addition, larger companies may not be able to attain the high growth rates of successful smaller companies and may be less capable of responding quickly to competitive challenges and industry changes. As a result, the Fund’s value may not rise as much as, or may fall more than, the value of funds that focus on companies with smaller market capitalizations.

Small- and Medium-Sized Company Risk. The Fund may invest in companies that are smaller, less established, with limited operating histories and less liquid markets for their stock, and therefore may be riskier investments. While small- and medium-sized companies generally have the potential for rapid growth, the securities of these companies often involve greater risks than investments in larger, more established companies because small- and medium-sized companies may lack the management experience, financial resources, product diversification and competitive strengths of larger companies. In addition, in many instances the securities of small- and medium-sized companies are traded only over-the-counter or on a regional securities exchange, and the frequency and volume of their trading is substantially less than is typical of larger companies. The value of securities of smaller, less well-known issuers can be more volatile than that of larger issuers.

Performance

Because the Fund had not yet commenced operations as of the date of this prospectus, there is no past performance to report. When performance data becomes available, it will be posted to the following website: www.driehaus.com/performance or by calling 1-800-560-6111. Of course, a Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.

Portfolio Management

Investment Adviser

Driehaus Capital Management LLC (“DCM”)

Portfolio Managers

Purchase and Sale of Fund Shares

In general, you can buy or sell shares of the Fund by regular mail addressed to Driehaus Mutual Funds, P.O. Box 4766, Chicago, IL 60680-4766, or by overnight delivery addressed to Driehaus Mutual Funds, c/o Northern Trust, 333 South Wabash Avenue, W-38, Chicago, IL 60604, or by phone at 1-800-560-6111 on any business day. You may also buy and sell shares through a financial professional.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gains, unless you are tax-exempt or are investing through a tax-advantaged arrangement, such as a 401(k) or an IRA. If you are investing through a tax-advantaged arrangement, assets held through such arrangement may be taxable upon withdrawal.

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’s related companies may pay the intermediary for the sale of Fund shares and/or related services, including recordkeeping, administrative and other sub-transfer agency 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.