Natixis Oakmark International Fund


	Summary Prospectus May 1, 2021

Ticker Symbol: Class A (NOIAX), Class C (NOICX), Class N (NIONX), Class T* (NIOTX) and Class Y (NOIYX)

*	Class T shares of the Fund are not currently available for purchase.

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus, reports to shareholders, and other information about the Fund online at im.natixis.com/fund-documents. You can also get this information at no cost by calling 800-225-5478 or by sending an e-mail request to NatixisFunds@natixis.com. The Fund’s Prospectus and Statement of Additional Information, each dated May 1, 2021, as may be revised or supplemented from time to time, are incorporated by reference into this Summary Prospectus.

Investment Goal

The Fund seeks long-term capital appreciation.

Fund Fees & Expenses

The following 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 this table. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Natixis Funds Complex. More information about these and other discounts is available from your financial professional and in the section “How Sales Charges Are Calculated” on page 75 of the Prospectus, in Appendix A to the Prospectus and on page 136 in the section “Reduced Sales Charges” of the Statement of Additional Information (“SAI”).

Shareholder Fees


(fees paid directly from your investment)	Class A	Class C	Class N	Class T	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	None	None	2.50%	None
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	None*	1.00%	None	None	None
Redemption fees	None	None	None	None	None

*	A 1.00% contingent deferred sales charge (“CDSC”) may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

Annual Fund Operating Expenses


(expenses that you pay each year as a percentage of the value of your investment)	Class A	Class C	Class N	Class T	Class Y
Management fees	0.78%	0.78%	0.78%	0.78%	0.78%
Distribution and/or service (12b-1) fees	0.25%	1.00%	0.00%	0.25%	0.00%
Other expenses¹	0.33%	0.33%	0.39%	0.33%²	0.33%
Total annual fund operating expenses	1.36%	2.11%	1.17%	1.36%	1.11%
Fee waiver and/or expense reimbursement³^,⁴	0.16%	0.16%	0.27%	0.16%	0.16%
Total annual fund operating expenses after fee waiver and/or expense reimbursement	1.20%	1.95%	0.90%	1.20%	0.95%

1	Other expenses include acquired fund fees and expenses of less than 0.01%.

2	Other expenses for Class T shares are estimated for the current fiscal year.

The Fund’s investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund’s total annual fund operating expenses to 1.20%, 1.95%, 0.90%, 1.20% and 0.95% of the Fund’s average daily net assets for Class A, C, N, T and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2022 and may be terminated before then only with the consent of the Fund’s Board of Trustees. The Fund’s investment adviser will be permitted to recover, on a class by class basis, management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below the applicable expense limitations for Class A, C, N, T and Y shares. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.

Natixis Advisors, L.P. (“Natixis Advisors”) has given a binding contractual undertaking to the Fund to reimburse any and all transfer agency expenses for Class N shares. This undertaking is in effect through April 30, 2022 and may be terminated before then only with the consent of the Fund’s Board of Trustees.

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 (except where indicated). The

Fund Summary

example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same, except that the example is based on the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement assuming that such waiver and/or reimbursement will only be in place through the date noted above and on the Total Annual Fund Operating Expenses for the remaining periods. The example for Class C shares for the ten-year period reflects the conversion to Class A shares after eight years. The example does not take into account brokerage commissions and other fees to financial intermediaries that you may pay on your purchases and sales of shares of the Fund. Although your actual costs may be higher or lower, based on these assumptions your costs would be:


If shares are redeemed:	1 year		3 years		5 years		10 years
Class A	$	690	$	966	$	1,262	$	2,103
Class C	$	298	$	645	$	1,119	$	2,237
Class N	$	92	$	345	$	618	$	1,396
Class T	$	369	$	655	$	961	$	1,831
Class Y	$	97	$	337	$	596	$	1,337


If shares are not redeemed:	1 year		3 years		5 years		10 years
Class C	$	198	$	645	$	1,119	$	2,237

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 for you if your 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 recently ended fiscal year, the Fund’s portfolio turnover rate was 63% of the average value of its portfolio.

Investments, Risks and Performance

Principal Investment Strategies

The Fund invests primarily in a diversified portfolio of common stocks of non-U.S. companies. The Fund may invest in non-U.S. markets throughout the world, including emerging markets. Ordinarily, the Fund will invest in the securities of at least five countries outside the U.S. There are no geographic limits on the Fund’s non-U.S. investments. Although the Fund invests primarily in common stocks of non-U.S. companies it may also invest in the securities of U.S. companies. The Fund may invest in the securities of small-, mid- and large-capitalization companies.

The Fund’s subadviser, Harris Associates L.P. (“Harris Associates”), uses a value investment philosophy in selecting equity securities, such as common stocks, preferred stocks, warrants, and securities convertible into common stocks and preferred stocks. This value investment philosophy is based upon the belief that, over time, a company’s stock price converges with Harris Associates’ estimate of its intrinsic value. By “intrinsic value,” Harris Associates means its estimate of the price a knowledgeable buyer would pay to acquire the entire business. Harris Associates believes that investing in securities priced significantly below what Harris Associates believes is a company’s intrinsic value presents the best opportunity to achieve the Fund’s investment objective.

Harris Associates uses this value investment philosophy to identify companies that have discounted stock prices compared to what Harris Associates believes are the companies’ intrinsic values. In assessing such companies, Harris Associates looks for the following characteristics, although not all of the companies selected will have these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of company management ownership.

Once Harris Associates identifies a stock that it believes is selling at a significant discount to Harris Associates’ estimated intrinsic value and that the issuer has one or more of the additional qualities mentioned above, Harris Associates generally will consider buying that security for the Fund. Harris Associates usually sells a security when the price approaches its estimated value or the issuer’s fundamentals change. Harris Associates monitors each holding and adjusts its price targets as warranted to reflect changes in the issuer’s fundamentals. The Fund’s portfolio typically holds 30 to 65 stocks.

Principal Investment Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund’s portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.

Equity Securities Risk: The value of the Fund’s investments in equity securities could be subject to unpredictable declines in the value of individual securities and periods of below-average performance in individual securities or in the equity market as a whole. Value stocks can perform differently from the market as a whole and from other types of stocks. Value stocks also present the risk that their lower valuations fairly reflect their business prospects and that investors will not agree that the stocks represent favorable investment opportunities, and they may fall out of favor with investors and underperform growth

Fund Summary

stocks during any given period. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds generally take precedence over the claims of those who own preferred stock or common stock.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit/counterparty and information risks. The Fund’s investments in foreign securities are also subject to foreign currency fluctuations and other foreign currency related risks. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Emerging Markets Risk: In addition to the risks of investing in foreign investments generally, emerging markets investments are subject to greater risks arising from political or economic instability, nationalization or confiscatory taxation, currency exchange restrictions, sanctions by other countries (such as the United States) and an issuer’s unwillingness or inability to make principal or interest payments on its obligations. Emerging markets companies may be smaller and have shorter operating histories than companies in developed markets.

Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. The Fund may be subject to currency risk because it may invest in currency-related instruments and may invest in securities or other instruments denominated in, or that generate income denominated in, foreign currencies. The Fund may elect not to hedge currency risk, or may hedge such risk imperfectly, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged.

Focused Investment Risk: Because the Fund may invest in a small number of industries or securities, it may have more risk because the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund’s net asset value.

Cybersecurity and Technology Risk: The Fund, its service providers, and other market participants increasingly depend on complex information technology and communications systems, which are subject to a number of different threats and risks that could adversely affect the Fund and its shareholders. Cybersecurity and other operational and technology issues may result in financial losses to the Fund and its shareholders.

Large Investor Risk: Ownership of shares of the Fund may be concentrated in one or a few large investors. Such investors may redeem shares in large quantities or on a frequent basis. Redemptions by a large investor can affect the performance of the Fund, may increase realized capital gains, including short-term capital gains taxable as ordinary income, may accelerate the realization of taxable income to shareholders and may increase transaction costs. These transactions potentially limit the use of any capital loss carryforwards and certain other losses to offset future realized capital gains (if any). Such transactions may also increase the Fund’s expenses.

Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result.

Market/Issuer Risk: The market value of the Fund’s investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund’s investments, such as management performance, financial condition and demand for the issuers’ goods and services.

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some 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 returns for the one-year, five-year, ten year and life-of-class periods (as applicable) compare to those of a broad measure of market performance. Class C shares will automatically convert to Class A shares after eight years.The Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available online at im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund’s shares. A sales charge will reduce your return.

Total Returns for Class A Shares


	Highest Quarterly Return: Fourth Quarter 2020, 31.94% Lowest Quarterly Return: First Quarter 2020, -38.74%

Fund Summary


Average Annual Total Returns
(for the periods ended December 31, 2020)	Past 1 Year	Past 5 Years	Past 10 Years	Life of Class N (5/1/17)
Class A - Return Before Taxes	-1.91%	5.33%	4.98%	-
Return After Taxes on Distributions	-1.84%	5.04%	4.66%	-
Return After Taxes on Distributions and Sale of Fund Shares	-0.96%	4.34%	4.10%	-
Class C - Return Before Taxes	2.28%	5.78%	4.98%	-
Class N - Return Before Taxes	4.44%	-	-	3.12%
Class T - Return Before Taxes	1.45%	6.06%	5.34%	-
Class Y - Return Before Taxes¹	4.32%	6.79%	5.70%	-
MSCI World ex USA Index (Net)	7.59%	7.64%	5.19%	7.06%

1	Prior to the inception of Class Y shares (5/1/17), performance is that of Class A shares and reflects the higher net expenses of that share class.

The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund’s other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.

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. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

The Return After Taxes on Distributions and the Return After Taxes on Distributions and Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from the pass-through of foreign tax credits and from losses on a sale of Fund shares at the end of the measurement period.

Management

Investment Adviser

Natixis Advisors, L.P. (“Natixis Advisors”)

Subadviser

Harris Associates L.P. (“Harris Associates”)

Portfolio Managers

David G. Herro, CFA^®, Deputy Chairman, Chief Investment Officer of International Equity and portfolio manager of Harris Associates, has served as co-portfolio manager of the Fund since 2010.

Michael L. Manelli, CFA^®, Vice President, portfolio manager, and analyst of Harris Associates, has served as co-portfolio manager of the Fund since 2016.

Purchase and Sale of Fund Shares

Class A and C Shares

The following chart shows the investment minimums for various types of accounts:


Type of Account	Minimum Initial Purchase		Minimum Subsequent Purchase
Any account other than those listed below	$	2,500	$	50
For shareholders participating in Natixis Funds’ Investment Builder Program	$	1,000	$	50
For Traditional IRA, Roth IRA, Rollover IRA, SEP-IRA and Keogh plans using the Natixis Funds’ prototype document (direct accounts, not held through intermediary)	$	1,000	$	50
Coverdell Education Savings Accounts using the Natixis Funds’ prototype document (direct accounts, not held through intermediary)	$	500	$	50

There is no initial or subsequent investment minimum for:

Fund Summary

•	Fee Based Programs (such as wrap accounts) where an advisory fee is paid to the broker-dealer or other financial intermediary. Please consult your financial representative to determine if your fee based program is subject to additional or different conditions or fees.

•	Certain Retirement Plans. Please consult your retirement plan administrator to determine if your retirement plan is subject to additional or different conditions or fees imposed by the plan administrator.

•	Clients of a Registered Investment Adviser where the Registered Investment Adviser receives an advisory, management or consulting fee.

The minimum investment requirements for Class A shares may be waived or lowered for investments effected through certain financial intermediaries that have entered into special arrangements with Natixis Distribution, L.P. (the “Distributor”). Consult your financial intermediary for additional information regarding the minimum investment requirement applicable to your investment.

Class N Shares

Class N shares of the Fund are subject to a $1,000,000 initial investment minimum. This minimum applies to Fee Based Programs and accounts (such as wrap accounts) where an advisory fee is paid to the broker-dealer or other financial intermediary, accounts established via a transfer, or any other transaction in which a new account is established. There is no subsequent investment minimum for these shares. There is no initial investment minimum for:

•	Certain Retirement Plans. Please consult your retirement plan administrator to determine if your retirement plan is subject to additional or different conditions or fees imposed by the plan administrator.

•	Sub-accounts held within an omnibus account, where the omnibus account has at least $1,000,000.

•	Funds of funds that are distributed by the Distributor.

In its sole discretion, the Distributor may waive the investment minimum requirement for accounts as to which the Distributor reasonably believes will have enough assets to exceed the investment minimum requirement within a relatively short period of time following the establishment date of such accounts in Class N. If, after two years, an account’s value does not exceed the investment minimum requirement, the Distributor and the Fund reserve the right to redeem such account.

Class T Shares

Class T shares of the Fund are not currently available for purchase.

Class T shares of the Fund may only be purchased by investors who are investing through an authorized third party, such as a broker-dealer or other financial intermediary, that has entered into a selling agreement with the Distributor. Investors may not hold Class T shares directly with the Fund. Class T shares are subject to a minimum initial investment of $2,500 and a minimum subsequent investment of $50. Not all financial intermediaries make Class T shares available to their clients.

Class Y Shares

Class Y shares of the Fund are generally subject to a minimum initial investment of $100,000 and a minimum subsequent investment of $50, except there is no minimum initial or subsequent investment for:

•	Fee Based Programs (such as wrap accounts) where an advisory fee is paid to the broker-dealer or other financial intermediary. Please consult your financial representative to determine if your fee based program is subject to additional or different conditions or fees.

•	Certain Retirement Plans. Please consult your retirement plan administrator to determine if your retirement plan is subject to additional or different conditions or fees imposed by the plan administrator.

•	Certain Individual Retirement Accounts if the amounts invested represent rollover distributions from investments by any of the retirement plans invested in the Fund.

•	Clients of a Registered Investment Adviser where the Registered Investment Adviser receives an advisory, management or consulting fee.

•

Fund Trustees, former Fund trustees, employees of affiliates of the Natixis Funds and other individuals who are affiliated with any Natixis Fund (this also applies to any spouse, parents, children, siblings, grandparents, grandchildren and in-laws of those mentioned) and Natixis affiliate employee benefit plans.

At the discretion of Natixis Advisors, L.P., clients of Natixis Advisors, L.P. and its affiliates may purchase Class Y shares of the Fund below the stated minimums.

Due to operational limitations at your financial intermediary, certain fee based programs, retirement plans, individual retirement accounts and accounts of registered investment advisers may be subject to the investment minimums described above.

The Fund’s shares are available for purchase and are redeemable on any business day through your investment dealer, directly from the Fund by writing to the Fund at Natixis Funds, P.O. Box 219579, Kansas City, MO 64121-9579, by exchange, by wire, by internet at im.natixis.com (certain restrictions may apply), through the Automated Clearing House system, or, in the case of redemptions, by telephone at 800-225-5478 or by the Systematic Withdrawal Plan.

Fund Summary

Tax Information

Fund distributions are generally taxable to you as ordinary income or capital gains, except for distributions to retirement plans and other investors that qualify for tax-advantaged treatment under U.S. federal income tax law generally. Investments in such tax-advantaged plans will generally be taxed only upon withdrawal of monies from the tax-advantaged arrangement.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of 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 the 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.

UOI77-0521