Putnam
High Income
Securities Fund

Annual report
8 | 31 | 17

Consider these risks before investing: Lower-rated bonds may offer higher yields in return for more risk. Bond investments are subject to interest-rate risk (the risk of bond prices falling if interest rates rise) and credit risk (the risk of an issuer defaulting on interest or principal payments). Interest-rate risk is greater for longer-term bonds, and credit risk is greater for below-investment-grade bonds. Unlike bonds, funds that invest in bonds have fees and expenses. Bond prices may fall or fail to rise over time for several reasons, including general financial market conditions, changing market perceptions (including perceptions about the risk of default and expectations about changes in monetary policy or interest rates), changes in government intervention, and factors related to a specific issuer or industry. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings. You can lose money by investing in the fund. The fund’s shares trade on a stock exchange at market prices, which may be lower than the fund’s net asset value.

Message from the Trustees

October 19, 2017

Dear Fellow Shareholder:

A fair amount of investor optimism has helped to fuel financial markets in 2017, and global stock and bond markets have generally fared well. At the same time, however, a number of macroeconomic and geopolitical risks around the world could disrupt the positive momentum.

While calm markets are generally welcome, we believe investors should continue to remember time-tested strategies: maintain a well-diversified portfolio, keep a long-term view, and speak regularly with your financial advisor. In the following pages, you will find an overview of your fund’s performance for the reporting period as well as an outlook for the coming months.

We would like to take this opportunity to recognize and thank Robert J. Darretta, John A. Hill, and W. Thomas Stephens, who recently retired from your fund’s Board of Trustees. We are grateful for their years of work on behalf of you and your fellow shareholders, and we wish them well in their future endeavors.

Thank you for investing with Putnam.

Putnam High Income Securities Fund offers investors a portfolio of high-yield corporate bonds and convertible securities. As a closed-end fund, it shares some common characteristics with open-end mutual funds, but there are some key differences that investors should understand as they consider their portfolio.

Looking at a closed-end fund’s performance

You will usually see that the NAV and the market price differ. The market price can be influenced by several factors that cause it to vary from the NAV, including fund distributions, changes in supply and demand for the fund’s shares, changing market conditions, and investor perceptions of the fund or its investment manager. A fund’s performance at market price typically differs from its results at NAV.

A hybrid portfolio for seeking returns

Though it carries commensurately greater risk, including the risk of corporate default and periodic illiquidity, the fund’s combination of security types can offer greater return potential than other types of bond funds. This is because of the higher-yielding nature of below-investment-grade corporate credit and because of the optionality embedded in convertibles, which allows shares to be exchanged for common stock.

Data are historical. Past performance does not guarantee future results. More recent returns may be less or more than those shown. Investment return and net asset value will fluctuate, and you may have a gain or a loss when you sell your shares. Performance assumes reinvestment of distributions and does not account for taxes. Fund returns in the bar chart are at NAV. See below and pages 10–11 for additional performance information, including fund returns at market price. Index and Lipper results should be compared with fund performance at NAV.

* The fund’s blended benchmark is an unmanaged index administered by Putnam Management, 50% of which is the JPMorgan Developed High Yield Index and 50% of which is the BofA Merrill Lynch Speculative Grade U.S. Convertible Index. The BofA Merrill Lynch Speculative Grade U.S. Convertible Index and the JPMorgan Developed High Yield Index were introduced on 12/31/92 and 12/31/94, respectively, which post-date the inception of the fund.

* The fund’s blended benchmark is an unmanaged index administrated by Putnam Management, 50% of which is the JPMorgan Developed High Yield Index and 50% of which is the BofA Merrill Lynch Speculative Grade U.S. Convertible Index.

This comparison shows your fund’s performance in the context of broad market indexes for the 12 months ended 8/31/17. See above and pages 10–11 for additional fund performance information. Index descriptions can be found on page 12.

Eric has an M.B.A. from the University of Chicago Booth School of Business and a B.S. from San Diego State University. He joined Putnam in 2000 and has been in the investment industry since 1994.

Rob has an M.B.A. from the University of Chicago Booth School of Business and a B.S. from the University of Pennsylvania Wharton School. He joined Putnam in 2000 and has been in the investment industry since 1986.

In addition to Eric and Rob, your fund is managed by Assistant Portfolio Manager Anthony Daigle.

How was the environment for convertible securities and high-yield bonds during the reporting period?

ERIC U.S. convertible bonds were one of the best-performing asset classes for the reporting period, posting a return of 15.63%, as measured by the BofA Merrill Lynch Speculative Grade U.S. Convertible Index [the convertibles index]. Much of the momentum came in the second half of the reporting period in response to optimism about the Trump administration’s proposed tax plan, the presidential election outcome in France, and improved corporate earnings. Given their high correlation with stocks, these hybrid securities benefited from the rally — capturing most of the rise in large-cap stocks, as measured by the 16.23% return for the S&P 500 Index, and exceeding the 14.91% rise in small-cap stocks, as measured by the Russell 2000 Index.

ROB U.S. high-yield bonds performed well, picking up steam as the period progressed due to steady demand for higher-yielding securities amid a generally supportive fundamental backdrop. Higher oil prices, potential fiscal and regulatory policy changes by the Trump administration, and modest new issuance also

Credit qualities are shown as a percentage of the fund’s net assets as of 8/31/17. A bond rated BBB or higher (A-3 or higher, for short-term debt) is considered investment grade. This chart reflects the highest security rating provided by one or more of Standard & Poor’s, Moody’s, and Fitch. Ratings and portfolio credit quality will vary over time.

Cash and net other assets, if any, represent the market value weights of cash, derivatives, and short-term securities in the portfolio. The fund itself has not been rated by an independent rating agency.

*Equity instruments are a combination of common stocks and convertible preferred stocks.

This table shows the fund’s top 10 individual holdings and the percentage of the fund’s net assets that each represented as of 8/31/17. Short-term investments and derivatives, if any, are excluded. Holdings may vary over time.

buoyed the asset class. In March 2017, high-yield bonds had a brief setback due to a sharp decline in oil prices and increasing prospects for higher interest rates. The high-yield market resumed its upward trajectory in April, trending higher despite periods of volatility in oil prices and interest rates. As expected, the Federal Reserve increased its benchmark for short-term interest rates by a quarter percentage point to a range of 1.00% to 1.25% at its June policy meeting. The asset class rose 9.45% for the 12-month period, as measured by the JPMorgan Developed High Yield Index [the high-yield index].

The fund delivered positive results but underperformed its benchmark, which is an equal weighted blend of the high-yield index and the convertibles index. What contributed to the fund’s performance during the reporting period?

ROB The fixed-income portion of the portfolio, which represented approximately 41.4% of total net assets on August 31, 2017, had positive absolute performance but underperformed the high-yield index for the period. Overweight portfolio allocations to the financials, housing, and gaming, lodging & leisure sectors were the largest relative contributors to fund performance. At the issuer level, an overweight position in Sprint Communications was the largest relative contributor due to the company’s positive earnings and discussions of a possible merger. Additionally, an overweight exposure to Scientific Games International also added to the fund’s results.

ERIC  The convertibles portion of the portfolio, which represented approximately 53.9% of total net assets on August 31, 2017, had positive absolute performance and outperformed the convertibles index for the period. Security selection within the technology and consumer cyclicals sectors, along with underweight positioning in energy, were the largest contributors on a relative basis. In the technology sector, an overweight position in the graphic processing chip developer, NVIDIA,

was the top relative contributor at the issuer level. The underlying equity appreciated due to the company’s expanding diversification, upgrades to its core products, and strong earnings results. NVIDIA was sold from the portfolio during the period to lock in profits. An out-of-benchmark exposure to LAM Research through portfolio holding Novellus Financial, which had previously merged with LAM, also augmented performance.

What detracted from the fund’s benchmark-relative performance?

ERIC Security selection within the consumer staples and financials sectors detracted from performance relative to the convertibles index. An overweight portfolio allocation to the health-care sector also detracted. At the issuer level, underweight positions in Microchip Technology, Advanced Micro Devices, and Micron Technology within the technology sector were the largest relative detractors for the period. The underlying equities of these issuers climbed in unison with the semiconductor market during the period. Advanced Micro Devices was sold from the portfolio prior to period-end.

ROB The largest detractors from fund performance relative to the high-yield index were underweight positions relative to this benchmark in the energy, technology, and services sectors. At the issuer level, our decision to underweight exposure to Caesars Entertainment was the top detractor, as the company benefited from finalizing its $18 billion bankruptcy. A slight overweight position in Concordia International also weighed on the fund’s returns due to weak fourth-quarter 2016 earnings. An overweight position in Neiman Marcus Group also weighed on performance

due to continued secular headwinds and weak earnings in the retail sector.

The fund reduced its dividend rate during the reporting period. What led to that decision?

ERIC The fund, which seeks high current income and capital appreciation, has maintained a stable dividend since August 2014. As a result of the low-interest-rate environment and lower coupons of securities in the portfolio, the fund’s monthly distribution rate was reduced from $0.0309 per share to $0.0283 per share in August 2017.

What is your outlook for the coming months, and how has this thinking influenced the fund’s positioning?

ROB Our overall view of the high-yield asset class remains generally constructive. We believe that, in the United States, the fundamental landscape of high-yield issuers continues to be stable, supported by a continuation of solid corporate earnings. Additionally, we believe high-yield issuers stand to benefit from deregulation, fiscal stimulus, and the potential for higher economic growth, although timing for implementation of these policies remains in question. Overall default levels have steadily fallen in 2017 through the end of the reporting period and reached levels last seen in 2014. From a valuation standpoint, although spreads are measurably tighter year-over-year, we believe they continue to look fair given stable fundamentals. Meanwhile, the technical environment has been relatively favorable, in our view, due to low net new issuance volumes.

With that being said, risks to our outlook include commodity price volatility, surprises from global central banks, heightened geopolitical tension, and/or a lack of policy follow-through from the Trump administration. Overall, our positioning remains consistent, and we will continue seeking to capitalize on relative value

This chart shows how the fund’s weightings have changed over the past six months. Allocations are shown as a percentage of the fund’s net assets. Cash and net other assets, if any, represent the market value weights of cash, derivatives, short-term securities, and other unclassified assets in the portfolio. Current period summary information may differ from the portfolio schedule included in the financial statements due to the inclusion of derivative securities, the exclusion of as-of trades, if any, the use of different classifications of securities for presentation purposes, and rounding. Holdings and allocations may vary over time.

opportunities in the primary and secondary high-yield markets.

ERIC The convertibles market continued to advance throughout the reporting period despite a more risk-off market sentiment. With equity valuations arguably stretched, geopolitical risk regarding North Korea intensifying, and progress on important U.S. legislation lacking, we believe convertibles can offer attractive risk-adjusted returns over time. Additionally, we believe the markets are currently anticipating a December 2017 interest-rate hike, which we expect will be supportive for the asset class. New issuance, which spiked in August, is expected to remain robust, although short-term volatility may impact the timing of certain deals.

To help the portfolio weather potential volatility, we are favoring what we view to be higher-quality names, along with higher market capitalization issuers. Additionally, we have trimmed exposure to securities in which the underlying equity valuations have become stretched, in our view. We have offset that exposure with new issues where opportunities presented themselves.

Thank you, gentlemen, for this update on the fund.

The views expressed in this report are exclusively those of Putnam Management and are subject to change. They are not meant as investment advice.

Please note that the holdings discussed in this report may not have been held by the fund for the entire period. Portfolio composition is subject to review in accordance with the fund’s investment strategy and may vary in the future. Current and future portfolio holdings are subject to risk.

Your fund’s performance

This section shows your fund’s performance, price, and distribution information for periods ended August 31, 2017, the end of its most recent fiscal year. In accordance with regulatory requirements for mutual funds, we also include performance information as of the most recent calendar quarter-end. Performance should always be considered in light of a fund’s investment strategy. Data represent past performance. Past performance does not guarantee future results. More recent returns may be less or more than those shown. Investment return, net asset value, and market price will fluctuate, and you may have a gain or a loss when you sell your shares.

Fund performance Total return for periods ended 8/31/17

Performance assumes reinvestment of distributions and does not account for taxes.

Performance is shown net of expenses.

Comparative index returns For periods ended 8/31/17

Index and Lipper results should be compared with fund performance at net asset value.

^* Over the 1-year, 3-year, 5-year, 10-year, and life-of-fund periods ended 8/31/17, there were 13, 11, 11, 11, and 2 funds, respectively, in this Lipper category.

^† The fund’s blended benchmark is an unmanaged index administered by Putnam Management, 50% of which is the JPMorgan Developed High Yield Index and 50% of which is the BofA Merrill Lynch Speculative Grade U.S. Convertible Index. The BofA Merrill Lynch Speculative Grade U.S. Convertible Index and the JPMorgan Developed High Yield Index were introduced on 12/31/92 and 12/31/94, respectively, which post-date the inception of the fund.

Fund price and distribution information For the 12-month period ended 8/31/17

The classification of distributions, if any, is an estimate. Final distribution information will appear on your year-end tax forms.

^* Most recent distribution, including any return of capital and excluding capital gains, annualized and divided by NAV or market price at end of period.

Fund performance as of most recent calendar quarter Total return for periods ended 9/30/17

See the discussion following the fund performance table on page 10 for information about the calculation of fund performance.

Terms and definitions

Important terms

Total return shows how the value of the fund’s shares changed over time, assuming you held the shares through the entire period and reinvested all distributions in the fund.

Net asset value (NAV) is the value of all your fund’s assets, minus any liabilities, divided by the number of outstanding shares.

Market price is the current trading price of one share of the fund. Market prices are set by transactions between buyers and sellers on exchanges such as the New York Stock Exchange.

Fixed-income terms

Current rate is the annual rate of return earned from dividends or interest of an investment. Current rate is expressed as a percentage of the price of a security, fund share, or principal investment.

Yield curve is a graph that plots the yields of bonds with equal credit quality against their differing maturity dates, ranging from shortest to longest. It is used as a benchmark for other debt, such as mortgage or bank lending rates.

Comparative indexes

Bloomberg Barclays U.S. Aggregate Bond Index is an unmanaged index of U.S. investment-grade fixed-income securities.

The fund’s blended benchmark is an unmanaged index administered by Putnam Management, 50% of which is the JPMorgan Developed High Yield Index and 50% of which is the BofA Merrill Lynch Speculative Grade U.S. Convertible Index.

BofA Merrill Lynch Speculative Grade U.S. Convertible Index is an unmanaged index of U.S. convertible securities.

BofA Merrill Lynch U.S. 3-Month Treasury Bill Index is an unmanaged index that seeks to measure the performance of U.S. Treasury bills available in the marketplace.

JPMorgan Developed High Yield Index is an unmanaged index of high-yield fixed-income securities issued in developed countries.

Russell^® 2000 Index is an unmanaged index of 2,000 small-cap companies in the Russell 3000 Index.

S&P 500 Index is an unmanaged index of common stock performance.

Indexes assume reinvestment of all distributions and do not account for fees. Securities and performance of a fund and an index will differ. You cannot invest directly in an index.

Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell^® is a trademark of Frank Russell Company.

Merrill Lynch, Pierce, Fenner & Smith Incorporated (“BofAML”), used with permission. BofAML permits use of the BofAML indices and related data on an “as is” basis, makes no warranties regarding same, does not guarantee the suitability, quality, accuracy, timeliness, and/or completeness of the BofAML indices or any data included in, related to, or derived therefrom, assumes no liability in connection with the use of the foregoing, and does not sponsor, endorse, or recommend Putnam Investments, or any of its products or services.

Lipper is a third-party industry-ranking entity that ranks mutual funds. Its rankings do not reflect sales charges. Lipper rankings are based on total return at net asset value relative to other funds that have similar current investment styles or objectives as determined by Lipper. Lipper may change a fund’s category assignment at its discretion. Lipper category averages reflect performance trends for funds within a category.

Other information for shareholders

Important notice regarding share repurchase program

In September 2017, the Trustees of your fund approved the renewal of a share repurchase program that had been in effect since 2005. This renewal allows your fund to repurchase, in the 12 months beginning October 10, 2017, up to 10% of the fund’s common shares outstanding as of October 9, 2017.

Important notice regarding delivery of shareholder documents

In accordance with Securities and Exchange Commission (SEC) regulations, Putnam sends a single copy of annual and semiannual shareholder reports, prospectuses, and proxy statements to Putnam shareholders who share the same address, unless a shareholder requests otherwise. If you prefer to receive your own copy of these documents, please call Putnam at 1-800-225-1581, and Putnam will begin sending individual copies within 30 days.

Proxy voting

Putnam is committed to managing our mutual funds in the best interests of our shareholders. The Putnam funds’ proxy voting guidelines and procedures, as well as information regarding how your fund voted proxies relating to portfolio securities during the 12-month period ended June 30, 2017, are available in the Individual Investors section of putnam.com, and on the SEC’s website, www.sec.gov. If you have questions about finding forms on the SEC’s website, you may call the SEC at 1-800-SEC-0330. You may also obtain the Putnam funds’ proxy voting guidelines and procedures at no charge by calling Putnam’s Shareholder Services at 1-800-225-1581.

Fund portfolio holdings

The fund will file a complete schedule of its portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. Shareholders may obtain the fund’s Form N-Q on the SEC’s website at www.sec.gov. In addition, the fund’s Form N-Q may be reviewed and copied at the SEC’s Public Reference Room in Washington, D.C. You may call the SEC at 1-800-SEC-0330 for information about the SEC’s website or the operation of the Public Reference Room.

Trustee and employee fund ownership

Putnam employees and members of the Board of Trustees place their faith, confidence, and, most importantly, investment dollars in Putnam mutual funds. As of August 31, 2017, Putnam employees had approximately $501,000,000 and the Trustees had approximately $89,000,000 invested in Putnam mutual funds. These amounts include investments by the Trustees’ and employees’ immediate family members as well as investments through retirement and deferred compensation plans.

Important notice regarding Putnam’s privacy policy

In order to conduct business with our shareholders, we must obtain certain personal information such as account holders’ names, addresses, Social Security numbers, and dates of birth. Using this information, we are able to maintain accurate records of accounts and transactions.

It is our policy to protect the confidentiality of our shareholder information, whether or not a shareholder currently owns shares of our funds. In particular, it is our policy not to sell information about you or your accounts to outside marketing firms. We have safeguards in place designed to prevent unauthorized access to our computer systems and procedures to protect personal information from unauthorized use.

Under certain circumstances, we must share account information with outside vendors who provide services to us, such as mailings and proxy solicitations. In these cases, the service providers enter into confidentiality agreements with us, and we provide only the information necessary to process transactions and perform other services related to your account. Finally, it is our policy to share account information with your financial representative, if you’ve listed one on your Putnam account.

Summary of Putnam Closed-End Funds’ Amended and Restated Dividend Reinvestment Plans

Putnam High Income Securities Fund, Putnam Managed Municipal Income Trust, Putnam Master Intermediate Income Trust, Putnam Municipal Opportunities Trust and Putnam Premier Income Trust (each, a “Fund” and collectively, the “Funds”) each offer a dividend reinvestment plan (each, a “Plan” and collectively, the “Plans”). If you participate in a Plan, all income dividends and capital gain distributions are automatically reinvested in Fund shares by the Fund’s agent, Putnam Investor Services, Inc. (the “Agent”). If you are not participating in a Plan, every month you will receive all dividends and other distributions in cash, paid by check and mailed directly to you.

Upon a purchase (or, where applicable, upon registration of transfer on the shareholder records of a Fund) of shares of a Fund by a registered shareholder, each such shareholder will be deemed to have elected to participate in that Fund’s Plan. Each such shareholder will have all distributions by a Fund automatically reinvested in additional shares, unless such shareholder elects to terminate participation in a Plan by instructing the Agent to pay future distributions in cash. Shareholders who were not participants in a Plan as of January 31, 2010, will continue to receive distributions in cash but may enroll in a Plan at any time by contacting the Agent.

If you participate in a Fund’s Plan, the Agent will automatically reinvest subsequent distributions, and the Agent will send you a confirmation in the mail telling you how many additional shares were issued to your account.

To change your enrollment status or to request additional information about the Plans, you may contact the Agent either in writing, at P.O. Box 8383, Boston, MA 02266-8383, or by telephone at 1-800-225-1581 during normal East Coast business hours.

How you acquire additional shares through a Plan If the market price per share for your Fund’s shares (plus estimated brokerage commissions) is greater than or equal to their net asset value per share on the payment date for a distribution, you will be issued shares of the Fund at a value equal to the higher of the net asset value per share on that date or 95% of the market price per share on that date.

If the market price per share for your Fund’s shares (plus estimated brokerage commissions) is less than their net asset value per share on the payment date for a distribution, the Agent will buy Fund shares for participating accounts in the open market. The Agent will aggregate open-market purchases on behalf of all participants, and the average price (including brokerage commissions) of all shares purchased by the Agent will be the price per share allocable to each participant. The Agent will generally complete these open-market purchases within five business days following the payment date. If, before the Agent has completed open-market purchases, the market price per share (plus estimated brokerage commissions) rises to exceed the net asset value per share on the payment date, then the purchase price may exceed the net asset value per share, potentially resulting in the acquisition of fewer shares than if the distribution had been paid in newly issued shares.

How to withdraw from a Plan Participants may withdraw from a Fund’s Plan at any time by notifying the Agent, either in writing or by telephone. Such withdrawal will be effective immediately if notice is received by the Agent with sufficient time prior to any distribution record date; otherwise, such withdrawal will be effective with respect to any subsequent distribution following notice of withdrawal. There is no penalty for withdrawing from or not participating in a Plan.

Plan administration The Agent will credit all shares acquired for a participant under a Plan to the account in which the participant’s common shares are held. Each participant will

be sent reasonably promptly a confirmation by the Agent of each acquisition made for his or her account.

About brokerage fees Each participant pays a proportionate share of any brokerage commissions incurred if the Agent purchases additional shares on the open market, in accordance with the Plans. There are no brokerage charges applied to shares issued directly by the Funds under the Plans.

About taxes and Plan amendments

Reinvesting dividend and capital gain distributions in shares of the Funds does not relieve you of tax obligations, which are the same as if you had received cash distributions. The Agent supplies tax information to you and to the IRS annually. Each Fund reserves the right to amend or terminate its Plan upon 30 days’ written notice. However, the Agent may assign its rights, and delegate its duties, to a successor agent with the prior consent of a Fund and without prior notice to Plan participants.

If your shares are held in a broker or nominee name If your shares are held in the name of a broker or nominee offering a dividend reinvestment service, consult your broker or nominee to ensure that an appropriate election is made on your behalf. If the broker or nominee holding your shares does not provide a reinvestment service, you may need to register your shares in your own name in order to participate in a Plan.

In the case of record shareholders such as banks, brokers or nominees that hold shares for others who are the beneficial owners of such shares, the Agent will administer the Plan on the basis of the number of shares certified by the record shareholder as representing the total amount registered in such shareholder’s name and held for the account of beneficial owners who are to participate in the Plan.

Trustee approval of management contract

General conclusions

The Board of Trustees of The Putnam Funds oversees the management of each fund and, as required by law, determines annually whether to approve the continuance of your fund’s management contract with Putnam Investment Management, LLC (“Putnam Management”) and the sub-management contract with respect to your fund between Putnam Management and its affiliate, Putnam Investments Limited (“PIL”). The Board, with the assistance of its Contract Committee, requests and evaluates all information it deems reasonably necessary under the circumstances in connection with its annual contract review. The Contract Committee consists solely of Trustees who are not “interested persons” (as this term is defined in the Investment Company Act of 1940, as amended (the “1940 Act”)) of The Putnam Funds (“Independent Trustees”).

At the outset of the review process, members of the Board’s independent staff and independent legal counsel discussed with representatives of Putnam Management the annual contract review materials furnished to the Contract Committee during the course of the previous year’s review, identifying possible changes in these materials that might be necessary or desirable for the coming year. Following these discussions and in consultation with the Contract Committee, the Independent Trustees’ independent legal counsel requested that Putnam Management and its affiliates furnish specified information, together with any additional information that Putnam Management considered relevant, to the Contract Committee. Over the course of several months ending in June 2017, the Contract Committee met on a number of occasions with representatives of Putnam Management, and separately in executive session, to consider the information that Putnam Management provided. Throughout this process, the Contract Committee was assisted by the members of the Board’s independent staff and by independent legal counsel for The Putnam Funds and the Independent Trustees.

In May 2017, the Contract Committee met in executive session to discuss and consider its recommendations with respect to the continuance of the contracts. At the Trustees’ June 2017 meeting, the Contract Committee met in executive session with the other Independent Trustees to review a summary of the key financial, performance and other data that the Contract Committee considered in the course of its review. The Contract Committee then presented its written report, which summarized the key factors that the Committee had considered and set forth its recommendations. The Contract Committee recommended, and the Independent Trustees approved, the continuance of your fund’s management and sub-management contracts, effective July 1, 2017. (Because PIL is an affiliate of Putnam Management and Putnam Management remains fully responsible for all services provided by PIL, the Trustees have not attempted to evaluate PIL as a separate entity, and all subsequent references to Putnam Management below should be deemed to include reference to PIL as necessary or appropriate in the context.)

The Independent Trustees’ approval was based on the following conclusions:

• That the fee schedule in effect for your fund represented reasonable compensation in light of the nature and quality of the services being provided to the fund, the fees paid by competitive funds, and the costs incurred by Putnam Management in providing services to the fund; and

• That the fee schedule in effect for your fund represented an appropriate sharing between fund shareholders and Putnam Management of such economies of scale as may exist in the management of the fund at current asset levels.

These conclusions were based on a comprehensive consideration of all information provided to the Trustees and were not the result of any single factor. Some of the factors that figured particularly in the Trustees’ deliberations and how the Trustees considered these factors are described below, although individual Trustees may have evaluated the information presented differently, giving different weights to various factors. It is also important to recognize that the management arrangements for your fund and the other Putnam funds are the result of many years of review and discussion between the Independent Trustees and Putnam Management, that some aspects of the arrangements may receive greater scrutiny in some years than others, and that the Trustees’ conclusions may be based, in part, on their consideration of fee arrangements in previous years.

Management fee schedules and total expenses

The Trustees reviewed the management fee schedules in effect for all Putnam funds, including fee levels and breakpoints. The Trustees also reviewed the total expenses of each Putnam fund, recognizing that in most cases management fees represented the major, but not the sole, determinant of total costs to fund shareholders. (In a few instances, funds have implemented so-called “all-in” management fees covering substantially all routine fund operating costs.)

In reviewing fees and expenses, the Trustees generally focus their attention on material changes in circumstances — for example, changes in assets under management, changes in a fund’s investment strategy, changes in Putnam Management’s operating costs or profitability, or changes in competitive practices in the mutual fund industry — that suggest that consideration of fee changes might be warranted. The Trustees concluded that the circumstances did not indicate that changes to the management fee structure for your fund would be appropriate at this time.

Under its management contract, your fund has the benefit of breakpoints in its management fee schedule that provide shareholders with economies of scale in the form of reduced fee rates as the fund’s assets under management increase. The Trustees noted, however, that because your fund is a closed-end management investment company, it has relatively stable levels of assets under management and is not expected to be affected significantly by breakpoints in its management fee schedule. The Trustees concluded that the fee schedule in effect for your fund represented an appropriate sharing of economies of scale between fund shareholders and Putnam Management.

The Trustees reviewed comparative fee and expense information for a custom group of competitive funds selected by Broadridge Financial Solutions, Inc. (“Broadridge”). This comparative information included your fund’s percentile ranking for effective management fees and total expenses, which provides a general indication of your fund’s relative standing. In the custom peer group, your fund ranked in the first quintile in effective management fees (determined for your fund and the other funds in the custom peer group based on fund asset size and the applicable contractual management fee schedule) and in the first quintile in total expenses as of December 31, 2016. The first quintile represents the least expensive funds and the fifth quintile the most expensive funds. The fee and expense data reported by Broadridge as of December 31, 2016 reflected the most recent fiscal year-end data available in Broadridge’s database at that time.

In connection with their review of fund management fees and total expenses, the Trustees also reviewed the costs of the services provided and the profits realized by Putnam Management and its affiliates from their contractual relationships with the funds. This information included trends in revenues, expenses and profitability of Putnam Management and its affiliates relating to the investment management, investor servicing and distribution services provided to the funds. In this regard, the Trustees also reviewed an analysis of Putnam Management’s revenues, expenses and profitability, allocated on a fund-by-fund basis, with respect to the funds’ management, distribution, and investor servicing contracts. For each fund, the analysis presented information about revenues, expenses and profitability for each of the agreements separately and for the agreements taken together on a combined basis. The Trustees concluded that, at current asset levels, the fee schedules in place represented reasonable compensation for the services being provided and represented an appropriate sharing between fund shareholders and Putnam Management of such economies of scale as may exist in the management of the Putnam funds at that time.

The information examined by the Trustees in connection with their annual contract review for the Putnam funds included information regarding fees charged by Putnam Management and its affiliates to institutional clients, including defined benefit pension and profit-sharing plans, charities, college endowments, foundations, sub-advised third-party mutual funds, state, local and non-U.S. government entities, and corporations. This information included, in cases where an institutional product’s investment strategy corresponds with a fund’s strategy, comparisons of those fees with fees charged to the Putnam funds, as well as an assessment of the differences in the services provided to these different types of clients as compared to the services provided to the Putnam Funds. The Trustees observed that the differences in fee rates between these clients and the Putnam funds are by no means uniform when examined by individual asset sectors, suggesting that differences in the pricing of investment management services to these types of clients may reflect, among other

things, historical competitive forces operating in separate markets. The Trustees considered the fact that in many cases fee rates across different asset classes are higher on average for mutual funds than for institutional clients, as well as the differences between the services that Putnam Management provides to the Putnam funds and those that it provides to its other clients. The Trustees did not rely on these comparisons to any significant extent in concluding that the management fees paid by your fund are reasonable.

Investment performance

The quality of the investment process provided by Putnam Management represented a major factor in the Trustees’ evaluation of the quality of services provided by Putnam Management under your fund’s management contract. The Trustees were assisted in their review of the Putnam funds’ investment process and performance by the work of the investment oversight committees of the Trustees, which meet on a regular basis with the funds’ portfolio teams and with the Chief Investment Officers and other senior members of Putnam Management’s Investment Division throughout the year. In addition, in response to a request from the Independent Trustees, Putnam Management provided the Trustees with in-depth presentations regarding each of the equity and fixed income investment teams, including the operation of the teams and their investment approaches. The Trustees concluded that Putnam Management generally provides a high-quality investment process — based on the experience and skills of the individuals assigned to the management of fund portfolios, the resources made available to them, and in general Putnam Management’s ability to attract and retain high-quality personnel — but also recognized that this does not guarantee favorable investment results for every fund in every time period.

The Trustees considered that 2016 was a challenging year for the performance of the Putnam funds, with generally disappointing results for the international and global equity funds and taxable fixed income funds, mixed results for small-cap equity, Spectrum, global asset allocation, equity research and tax exempt fixed income funds, but generally strong results for U.S. equity funds. The Trustees noted, however, that they were encouraged by the positive performance trend since mid-year 2016 across most Putnam Funds. In particular, from May 1, 2016 through April 30, 2017, 51% of Putnam Fund assets were in the top quartile and 87% were above the median of the Putnam Funds’ competitive industry rankings. They noted that the longer-term performance of the Putnam funds generally continued to be strong, exemplified by the fact that the Putnam funds were ranked by the Barron’s/Lipper Fund Families survey as the 5th-best performing mutual fund complex out of 54 complexes for the five-year period ended December 31, 2016. In addition, while the survey ranked the Putnam Funds 52nd out of 61 mutual fund complexes for the one-year period ended 2016, the Putnam Funds have ranked 1st or 2nd in the survey for the one-year period three times since 2009 (most recently in 2013). They also noted, however, the disappointing investment performance of some funds for periods ended December 31, 2016 and considered information provided by Putnam Management regarding the factors contributing to the underperformance and actions being taken to improve the performance of these particular funds. The Trustees indicated their intention to continue to monitor closely the performance of those funds, including the effectiveness of any efforts Putnam Management has undertaken to address underperformance and whether additional actions to address areas of underperformance are warranted.

For purposes of the Trustees’ evaluation of the Putnam Funds’ investment performance, the Trustees generally focus on a competitive industry ranking of each fund’s total net return over a one-year, three-year and five-year period. For a number of Putnam funds with relatively unique investment mandates for which Putnam Management informed the Trustees that meaningful competitive performance rankings are not considered to be available, the Trustees evaluated performance based on their total gross and net returns and, in most cases, comparisons of those returns with the returns of selected investment benchmarks. In the case of your fund, the Trustees considered that its common share cumulative total return performance at net asset value was in the following quartiles of its Lipper Inc. (“Lipper”) peer group (Lipper Convertible Securities Funds (closed-end)) for the one-year, three-year and five-year periods ended December 31, 2016 (the first quartile representing the best-performing funds and the fourth quartile the worst-performing funds):

Over the one-year, three-year and five-year periods ended December 31, 2016, there were 13, 11 and 11 funds, respectively, in your fund’s Lipper peer group. (When considering performance information, shareholders should be mindful that past performance is not a guarantee of future results.)

The Trustees also considered Putnam Management’s continued efforts to support fund performance through initiatives including structuring compensation for portfolio managers and research analysts to enhance accountability for fund performance, emphasizing accountability in the portfolio management process, and affirming its commitment to a fundamental-driven approach to investing. The Trustees noted further that Putnam Management continued to strengthen its fundamental research capabilities by adding new investment personnel.

Brokerage and soft-dollar allocations; investor servicing

The Trustees considered various potential benefits that Putnam Management may receive in connection with the services it provides under the management contract with your fund. These include benefits related to brokerage allocation and the use of soft dollars, whereby a portion of the commissions paid by a fund for brokerage may be used to acquire research services that are expected to be useful to Putnam Management in managing the assets of the fund and of other clients. Subject to policies established by the Trustees, soft dollars generated by these means are used predominantly to acquire brokerage and research services (including third-party research and market data) that enhance Putnam Management’s investment capabilities and supplement Putnam Management’s internal research efforts. However, the Trustees noted that a portion of available soft dollars continues to be used to pay fund expenses. The Trustees indicated their continued intent to monitor regulatory and industry developments in this area with the assistance of their Brokerage Committee, including any developments with respect to the European Union’s updated Markets in Financial Instruments Directive and its potential impact on PIL’s use of client commissions to obtain investment research. The Trustees also indicated their continued intent to monitor the allocation of the Putnam funds’ brokerage in order to ensure that the principle of seeking best price and execution remains paramount in the portfolio trading process.

Putnam Management may also receive benefits from payments that the funds make to Putnam Management’s affiliates for investor services. In conjunction with the annual review of your fund’s management and sub-management contracts, the Trustees reviewed your fund’s investor servicing agreement with Putnam Investor Services, Inc. (“PSERV”), which is an affiliate of Putnam Management. The Trustees concluded that the fees payable by the funds to PSERV for such services are fair and reasonable in relation to the nature and quality of such services, the fees paid by competitive funds, and the costs incurred by PSERV in providing such services. Furthermore, the Trustees were of the view that the services provided were required for the operation of the funds, and that they were of a quality at least equal to those provided by other providers.

Financial statements

These sections of the report, as well as the accompanying Notes, preceded by the Report of Independent Registered Public Accounting Firm, constitute the fund’s financial statements.

The fund’s portfolio lists all the fund’s investments and their values as of the last day of the reporting period. Holdings are organized by asset type and industry sector, country, or state to show areas of concentration and diversification.

Statement of assets and liabilities shows how the fund’s net assets and share price are determined. All investment and non-investment assets are added together. Any unpaid expenses and other liabilities are subtracted from this total. The result is divided by the number of shares to determine the net asset value per share. (For funds with preferred shares, the amount subtracted from total assets includes the liquidation preference of preferred shares.)

Statement of operations shows the fund’s net investment gain or loss. This is done by first adding up all the fund’s earnings — from dividends and interest income — and subtracting its operating expenses to determine net investment income (or loss). Then, any net gain or loss the fund realized on the sales of its holdings — as well as any unrealized gains or losses over the period — is added to or subtracted from the net investment result to determine the fund’s net gain or loss for the fiscal year.

Statement of changes in net assets shows how the fund’s net assets were affected by the fund’s net investment gain or loss, by distributions to shareholders, and by changes in the number of the fund’s shares. It lists distributions and their sources (net investment income or realized capital gains) over the current reporting period and the most recent fiscal year-end. The distributions listed here may not match the sources listed in the Statement of operations because the distributions are determined on a tax basis and may be paid in a different period from the one in which they were earned.

Financial highlights provide an overview of the fund’s investment results, per-share distributions, expense ratios, net investment income ratios, and portfolio turnover in one summary table, reflecting the five most recent reporting periods. In a semiannual report, the highlights table also includes the current reporting period.

Report of Independent Registered Public Accounting Firm

To the Trustees and Shareholders
of Putnam High Income Securities Fund:

In our opinion, the accompanying statement of assets and liabilities, including the portfolio, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of Putnam High Income Securities Fund (the “Fund”) as of August 31, 2017, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended and the financial highlights for each of the five years in the period then ended, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as “financial statements”) are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of August 31, 2017 by correspondence with the custodian and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP
Boston, Massachusetts
October 19, 2017

The fund’s portfolio 8/31/17