Prospectus Supplement	January 17, 2018
Putnam Multi-Cap Growth Fund
Prospectus dated October 30, 2017

Effective January 17, 2018, the sub-section Portfolio manager in the section Fund summary – Your fund’s management is replaced in its entirety with the following:

Portfolio managers
Katherine Collins, Head of Sustainable Investing, portfolio manager of the fund since 2018
R. Shepherd Perkins, Portfolio Manager, portfolio manager of the fund since 2018

Also effective January 17, 2018, the following replaces similar disclosure under the sub-section The fund’s investment manager – Portfolio manager in the section Who oversees and manages the fund?

• Portfolio managers. The officers of Putnam Management identified below are primarily responsible for the day-to-day management of the fund’s portfolio.

Portfolio managers	Joined fund	Employer	Positions over past five years
Katherine Collins	2018	Putnam	Head of Sustainable Investing
		Management
		2017 – Present
		Honeybee Capital	Founder and Chief Executive Officer
		2009 – 2017
		Putnam	Co-Head of Equities
R. Shepherd Perkins	2018	Management
		2011 – Present

The SAI provides information about these individuals’ compensation, other accounts managed by these individuals and these individuals’ ownership of securities in the fund.

Putnam Investment Management, LLC (“Putnam Management) has recommended changes to the fund’s investment strategy in order to incorporate sustainability criteria, as described in more detail below. Putnam Management currently anticipates that the changes will be effective on or about March 19, 2018 (the Effective Date).

Implementing these changes in the fund’s portfolio will result in certain brokerage commission and other transaction costs, which are expected to be incurred largely in March 2018. Depending on market conditions at the time, these changes could also result in realization of capital gains.

On the Effective Date, the fund’s name will change to “Putnam Sustainable Leaders Fund,” and the fund’s principal investment strategies and principal risks will be changing as described below. Accordingly, on the Effective Date, the following changes are made in the fund’s Prospectus:

• All references in the Prospectus to Putnam Multi-Cap Growth Fund are deleted and replaced with “Putnam Sustainable Leaders Fund.”

• Similar information in the sub-sections Investments and Risks in the section Fund summary – Investments, risks and performance is superseded and replaced with the following:

Investments

We invest mainly in common stocks of U.S. companies of any size, with a focus on growth stocks of companies that we believe exhibit a commitment to sustainable business practices. Growth stocks are stocks of companies whose earnings are expected to grow faster than those of similar firms, and whose business growth and other characteristics may lead to an increase in stock price. We consider sustainability factors, as described below, and may consider other factors, such as a company’s valuation, financial strength, growth potential, competitive position in its industry, projected future earnings, cash flows and dividends when deciding whether to buy or sell investments.

Sustainable investing. In selecting investments, we focus on companies that we believe have a demonstrated commitment to sustainable business practices. This commitment may be reflected through environmental, social and/or corporate governance (ESG) policies, practices or outcomes.

Risks

It is important to understand that you can lose money by investing in the fund.

The value of stocks in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general financial market conditions, changing market perceptions, changes in government intervention in the financial markets, and factors related to a specific issuer, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. Growth stocks may be more susceptible to earnings disappointments, and the market may not favor growth-style investing. These risks are generally greater for small and midsize companies. From time to time, the fund may invest a significant portion of its assets in companies in one or more related industries or sectors, which would make the fund more vulnerable to adverse developments affecting those industries or sectors.

Investing with a focus on companies that exhibit a commitment to sustainable business practices may cause the fund to forego otherwise attractive investment opportunities or may increase or decrease the fund’s exposure to certain types of companies and, therefore, to underperform funds that do not invest with a similar focus. In evaluating an investment opportunity, we may make investment decisions based on information and data that is incomplete or inaccurate. In addition, a company’s business practices may change over time. As a result of these possibilities, the fund

may temporarily hold securities that are inconsistent with the fund’s sustainable investment criteria.

The fund may not achieve its goal, and it is not intended to be a complete investment program. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The rest of the section remains the same.

• The similar information in the section What are the fund’s main investment strategies and related risks is superseded and replaced with the following:

What are the fund's main investment strategies and related risks?

This section contains greater detail on the fund’s main investment strategies and the related risks you would face as a fund shareholder. It is important to keep in mind that risk and reward generally go hand in hand; the higher the potential reward, the greater the risk. As mentioned in the fund summary, we pursue the fund's goal by investing mainly in growth stocks of U.S. companies of any size, with a focus on companies that exhibit a commitment to sustainable business practices.

• Sustainable business practices. The fund focuses its investments in companies that exhibit a commitment to sustainable business practices. The fund’s approach to sustainable investing incorporates fundamental research together with consideration of environmental, social and governance (ESG) criteria. Environmental factors include, for example, a company’s carbon intensity and plans to improve use of resources like water or minerals. Sustainability measures in the area might include plans to reduce waste, increase recycling, or improve produce design to be less resource intensive. Social criteria include, for example, labor practices and supply chain management. Sustainability measures in this area might include programs to improve employee well-being, commitment to workplace equality and diversity, or improved stewardship of supplier relationships and working conditions. Corporate governance factors include, for example, board composition and executive compensation. Sustainability measures in this area might include improvements in board independence or diversity, or alignment of management incentives with the company’s strategic sustainability objectives.

•Common stocks. Common stock represents an ownership interest in a company. The value of a company’s stock may fall as a result of factors directly relating to that company, such as decisions made by its management or lower demand for the company’s products or services. A stock’s value may also fall because of factors affecting not just the company, but also other companies in the same industry or in a number of different industries, such as increases in production costs. From time to time, the fund may invest a significant portion of its assets in issuers in one or more related industries or sectors, which would make the fund more vulnerable to adverse developments affecting those issuers, industries or sectors. The value of a company’s stock may also be affected by changes in financial markets that are relatively unrelated to the company or its industry, such as changes in interest rates or currency exchange rates. In addition, a company’s stock generally pays dividends only after the company invests in its own business

and makes required payments to holders of its bonds and other debt. For this reason, the value of a company’s stock will usually react more strongly than its bonds and other debt to actual or perceived changes in the company’s financial condition or prospects.

Growth stocks -- Stocks of companies we believe are fast-growing may trade at a higher multiple of current earnings than other stocks. The values of these stocks may be more sensitive to changes in current or expected earnings than the values of other stocks. If our assessment of the prospects for a company's earnings growth is wrong, or if our judgment of how other investors will value the company's earnings growth is wrong, then the price of the company's stock may fall or may not approach the value that we have placed on it. In addition, growth stocks, at times, may not perform as well as value stocks or the stock market in general, and may be out of favor with investors for varying periods of time.

• Small and midsize companies. These companies, some of which may have a market capitalization of less than $1 billion, are more likely than larger companies to have limited product lines, markets or financial resources, lack profitability, or depend on a small management group. Stocks of these companies often trade in smaller volumes, and their prices may fluctuate more than stocks of larger companies. Stocks of small and midsize companies may therefore be more vulnerable to adverse developments than those of larger companies. In addition, stocks of small and midsize companies, at times, may not perform as well as stocks of larger companies or the stock market in general, and may be out of favor with investors for varying periods of time.

•Foreign investments. We may invest in foreign investments, although they do not represent a primary focus of the fund. Foreign investments involve certain special risks. For example, their values may decline in response to changes in currency exchange rates, unfavorable political and legal developments, unreliable or untimely information, and economic and financial instability. In addition, the liquidity of these investments may be more limited than for most U.S. investments, which means we may at times be unable to sell them at desirable prices. Foreign settlement procedures may also involve additional risks. These risks are generally greater in the case of developing (also known as emerging) markets, which typically have less developed legal and financial systems.

Certain of these risks may also apply to some extent to U.S.-traded investments that are denominated in foreign currencies, investments in U.S. companies that are traded in foreign markets, or investments in U.S. companies that have significant foreign operations.

•Derivatives. We may engage in a variety of transactions involving derivatives, such as futures, options, warrants and swap contracts, although they do not represent a primary focus of the fund. Derivatives are financial instruments whose value depends upon, or is derived from, the value of something else, such as one or more underlying investments, pools of investments, indexes or currencies. We may make use of "short" derivatives positions, the values of which typically move in the opposite direction from the price of the underlying investment, pool of investments, index or currency. We may use derivatives both for hedging and non-hedging purposes, including as a substitute for a direct investment in the securities of one or more issuers. However, we may also choose not to use derivatives based on our evaluation of market conditions or the availability of suitable derivatives. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on our ability to manage these sophisticated instruments. Some derivatives are "leveraged," which means they provide the fund with investment exposure greater than the value of the fund's investment in the derivatives. As a result, these derivatives may magnify or otherwise increase investment losses to the fund. The risk of loss from certain short derivatives positions is theoretically unlimited. The value of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility.

Other risks arise from the potential inability to terminate or sell derivatives positions. A liquid secondary market may not always exist for the fund's derivatives positions. In fact, many over-the-counter instruments (investments not traded on an exchange) will not be liquid. Over-the-counter instruments also involve the risk that the other party to the derivatives transaction will not meet its obligations. For further information about the additional types and risks of derivatives and the fund's asset segregation policies, see Miscellaneous Investments, Investment Practices and Risks in the SAI.

•Market risk. The value of securities in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general financial market conditions, changing market perceptions, changes in government intervention in the financial markets, and factors related to a specific issuer, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. During those periods, the fund may experience high levels of shareholder redemptions, and may have to sell securities at times when it would otherwise not do so, and at unfavorable prices.

•Other investments. In addition to the main investment strategies described above, the fund may make other types of investments, such as investments in preferred stocks, convertible securities, and debt instruments. The fund may also loan portfolio securities to earn income. These practices may be subject to other risks, as described under Miscellaneous Investments, Investment Practices and Risks in the SAI.

•Temporary defensive strategies. In response to adverse market, economic, political or other conditions, we may take temporary defensive positions, such as investing some or all of the fund's assets in cash and cash equivalents, that differ from the fund's usual investment strategies. However, we may choose not to use these temporary defensive strategies for a variety of reasons, even in very volatile market conditions. These strategies may cause the fund to miss out on investment opportunities, and may prevent the fund from achieving its goal. Additionally, while temporary defensive strategies are mainly designed to limit losses, such strategies may not work as intended.

•Changes in policies. The Trustees may change the fund's goal, investment strategies and other policies set forth in this prospectus without shareholder approval, except as otherwise provided.

•Portfolio turnover rate. The fund’s portfolio turnover rate measures how frequently the fund buys and sells investments. A portfolio turnover rate of 100%, for example, would mean that the fund sold and replaced securities valued at 100% of the fund’s assets within a one-year period. From time to time the fund may engage in frequent trading. Funds with high turnover may be more likely to realize capital gains that must be distributed to shareholders as taxable income. High turnover may also cause a fund to pay more brokerage commissions and other transaction

costs, which may detract from performance. The fund’s portfolio turnover rate and the amount of brokerage commissions it pays will vary over time based on market conditions.

•Portfolio holdings. The SAI includes a description of the fund's policies with respect to the disclosure of its portfolio holdings. For more specific information on the fund's portfolio, you may visit the Putnam Investments website, putnam.com/individual, where the fund's top 10 holdings and related portfolio information may be viewed monthly beginning approximately 15 days after the end of each month, and full portfolio holdings may be viewed beginning on the last business day of the month after the end of each calendar quarter. This information will remain available on the website until the fund files a Form N-CSR or N-Q with the SEC for the period that includes the date of the information, after which such information can be found on the SEC's website at http://www.sec.gov.

The rest of the section remains the same.

Shareholders should retain this Supplement for future reference. 

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