NATIXIS FUNDS

Supplement dated April 2, 2018 to the Natixis Funds Prospectuses, dated February 1, 2018, May 1, 2017, and February 28, 2017, as may be revised or supplemented from time to time, for the following funds.

AEW Real Estate Fund	Loomis Sayles Limited Term Government and Agency Fund
ASG Dynamic Allocation Fund	Loomis Sayles Multi-Asset Income Fund
ASG Global Alternatives Fund	Loomis Sayles Strategic Alpha Fund
ASG Managed Futures Strategy Fund	Loomis Sayles Strategic Income Fund
ASG Tactical U.S. Market Fund	Loomis Sayles Value Fund
Gateway Equity Call Premium Fund	McDonnell Intermediate Municipal Bond Fund
Gateway Fund	Mirova Global Green Bond Fund
Loomis Sayles Core Plus Bond Fund	Mirova Global Sustainable Equity Fund
Loomis Sayles Global Allocation Fund	Natixis Oakmark Fund
Loomis Sayles Growth Fund	Natixis Oakmark International Fund
Loomis Sayles High Income Fund	Natixis U.S. Equity Opportunities Fund
Loomis Sayles Intermediate Duration Bond Fund	Vaughan Nelson Small Cap Value Fund
Loomis Sayles Investment Grade Bond Fund	Vaughan Nelson Value Opportunity Fund

Effective immediately, the following information is added to Appendix A to each Prospectus:

Ameriprise Financial

Class A Shares Front-End Sales Charge Waivers Available at Ameriprise Financial:

The following information applies to Class A shares purchases if you have an account with or otherwise purchase Fund shares through Ameriprise Financial:

Effective June 1, 2018, shareholders purchasing Fund shares through an Ameriprise Financial platform or account will be eligible for the following front-end sales charge waivers and discounts, which may differ from those disclosed elsewhere in this Fund’s prospectus or SAI:

• Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs or SAR-SEPs.

• Shares purchased through an Ameriprise Financial investment advisory program (if an Advisory or similar share class for such investment advisory program is not available).

• Shares purchased by third party investment advisors on behalf of their advisory clients through Ameriprise Financial’s platform (if an Advisory or similar share class for such investment advisory program is not available).

• Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same Fund (but not any other fund within the same fund family).

• Shares exchanged from Class C shares of the same fund in the month of or following the 10-year anniversary of the purchase date. To the extent that this prospectus elsewhere provides for a waiver with respect to such shares following a shorter holding period, that waiver will apply to exchanges following such shorter period. To the extent that this prospectus elsewhere provides for a waiver with respect to exchanges of Class C shares for load waived shares, that waiver will also apply to such exchanges.

• Employees and registered representatives of Ameriprise Financial or its affiliates and their immediate family members.

• Shares purchased by or through qualified accounts (including IRAs, Coverdell Education Savings Accounts, 401(k)s, 403(b) TSCAs subject to ERISA and defined benefit plans) that are held by a covered family member, defined as an Ameriprise financial advisor and/or the advisor’s spouse, advisor’s lineal ascendant (mother, father, grandmother, grandfather, great grandmother, great grandfather), advisor’s lineal descendant (son, step-son, daughter, stepdaughter, grandson, granddaughter, great grandson, great granddaughter) or any spouse of a covered family member who is a lineal descendant.

• Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred sales load (i.e. Rights of Reinstatement).

Morgan Stanley Wealth Management

Effective July 1, 2018, shareholders purchasing Fund shares through a Morgan Stanley Wealth Management transactional brokerage account will be eligible only for the following front-end sales charge waivers with respect to Class A shares, which may differ from and may be more limited than those disclosed elsewhere in this Fund’s Prospectus or SAI.

Front-end Sales Charge Waivers on Class A Shares available at Morgan Stanley Wealth Management

• Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs, SAR-SEPs or Keogh plans

• Morgan Stanley employee and employee-related accounts according to Morgan Stanley’s account linking rules

• Shares purchased through reinvestment of dividends and capital gains distributions when purchasing shares of the same fund

• Shares purchased through a Morgan Stanley self-directed brokerage account

• Class C (i.e., level-load) shares that are no longer subject to a contingent deferred sales charge and are converted to Class A shares of the same fund pursuant to Morgan Stanley Wealth Management’s share class conversion program

• Shares purchased from the proceeds of redemptions within the same fund family, provided (i) the repurchase occurs within 90 days following the redemption, (ii) the redemption and purchase occur in the same account, and (iii) redeemed shares were subject to a front-end or deferred sales charge.