May 28, 2021

BlackRock Real Estate Securities Fund

Fund Overview Key Facts About BlackRock Real Estate Securities Fund

Investment Objective

The investment objective of BlackRock Real Estate Securities Fund (the “Fund”), a series of BlackRock FundsSM (the “Trust”), is to seek total return comprised of long-term growth of capital and dividend income.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each, a “Financial Intermediary”), which are not reflected in the table and example below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in the fund complex advised by BlackRock or its affiliates. More information about these and other discounts is available from your Financial Intermediary and in the “Details About the Share Classes” and the “Intermediary-Defined Sales Charge Waiver Policies” sections on pages 22 and A-1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II-86 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

A contingent deferred sales charge (“CDSC”) of 1.00% is assessed on certain redemptions of Investor A Shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

You would pay the following expenses if you did not redeem your shares:

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 the most recent fiscal year, the Fund’s portfolio turnover rate was 58% of the average value of its portfolio.

Principal Investment Strategies of the Fund

Under normal conditions, the Fund invests at least 80% of its net assets plus any borrowings for investment purposes (measured at the time of purchase) in a portfolio of equity investments in issuers that are primarily engaged in or related to the real estate industry inside the United States. An issuer is primarily engaged in or related to the real estate industry if it derives at least 50% of its gross revenues or net profits from the ownership, development, construction, financing, management or sale of commercial, industrial or residential real estate or interests therein or has 50% of its assets in real estate or real estate interests. The Fund may invest up to 20% of its net assets plus any borrowings for investment purposes (measured at the time of purchase) in a portfolio of equity investments in issuers that are primarily engaged in or related to the real estate industry outside the United States and fixed-income investments, such as government, corporate and bank debt obligations. Real estate industry companies may include real estate investment trusts (“REITs”), REIT-like structures, or real estate operating companies whose businesses and services are related to the real estate industry. The Fund primarily buys common stock but also can invest in preferred stock and convertible securities. The Fund concentrates its investments in securities of issuers in the real estate industry. The Fund is classified as non-diversified under the Investment Company Act of 1940, as amended.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of the principal risks of investing in the Fund. The order of the below risk factors does not indicate the significance of any particular risk factor. ■ Concentration Risk — The Fund’s strategy of concentrating in the real estate industry means that its performance will be closely tied to the performance of a particular market segment. The Fund’s concentration in these companies may present more risks than if it were broadly diversified over numerous industries and sectors of the economy. A downturn in these companies would have a larger impact on the Fund than on a mutual fund that does not concentrate in such companies. At times, the performance of these companies will lag the performance of other industries or the broader market as a whole. In addition, the real estate industry has historically experienced substantial price volatility. ■ Convertible Securities Risk — The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer’s credit rating or the market’s perception of the issuer’s creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock. ■ Equity Securities Risk — Stock markets are volatile. The price of equity securities fluctuates based on changes in a company’s financial condition and overall market and economic conditions. ■ Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.   A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time. ■ Non-Diversification Risk — The Fund is a non-diversified fund. Because the Fund may invest in securities of a smaller number of issuers, it may be more exposed to the risks associated with and developments affecting an individual issuer than a fund that invests more widely. ■ Preferred Securities Risk — Preferred securities may pay fixed or adjustable rates of return. Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company’s preferred securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred securities of smaller companies may be more vulnerable to adverse developments than preferred securities of larger companies. ■ Real Estate-Related Securities Risk — The main risk of real estate-related securities is that the value of the underlying real estate may go down. Many factors may affect real estate values. These factors include both the general and local economies, vacancy rates, tenant bankruptcies, the ability to re-lease space under expiring leases on attractive terms, the amount of new construction in a particular area, the laws and regulations (including zoning, environmental and tax laws) affecting real estate and the costs of owning, maintaining and improving real estate. The availability of mortgage financing and changes in interest rates may also affect real estate values. If the Fund’s real estate-related investments are concentrated in one geographic area or in one property type, the Fund will be particularly subject to the risks associated with that area or property type. Many issuers of real estate-related securities are highly leveraged, which increases the risk to holders of such securities. The value of the securities the Fund buys will not necessarily track the value of the underlying investments of the issuers of such securities. ■ REIT Investment Risk — Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, may engage in dilutive offerings of securities and may be more volatile than other securities. REIT issuers may also fail to maintain their exemptions from investment company registration or fail to qualify for the “dividends paid deduction” under the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”), which allows REITs to reduce their corporate taxable income for dividends paid to their shareholders. ■ Small and Mid-Capitalization Company Risk — Companies with small or mid-size market capitalizations will normally have more limited product lines, markets and financial resources and will be dependent upon a more limited management group than larger capitalized companies. In addition, it is more difficult to get information on smaller companies, which tend to be less well known, have shorter operating histories, do not have significant ownership by large investors and are followed by relatively few securities analysts.

Performance Information

The information shows you how the Fund’s performance has varied for the periods since inception and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the FTSE EPRA Nareit United States Index and the MSCI U.S. REIT Index. Effective June 1, 2020, the Fund changed its benchmark from the FTSE EPRA Nareit United States Index to the MSCI U.S. REIT Index, as BlackRock considers this benchmark to be more representative of the sectors in which the Fund invests. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting www.blackrock.com or can be obtained by phone at (800) 882-0052.

Investor A Shares ANNUAL TOTAL RETURNS BlackRock Real Estate Securities Fund As of 12/31

During the periods shown in the bar chart, the highest return for a quarter was 16.89% (quarter ended March 31, 2019) and the lowest return for a quarter was -24.07% (quarter ended March 31, 2020). The year-to-date return as of March 31, 2021 was 9.75%.

For the periods ended 12/31/20 Average Annual Total Returns

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 the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Investor C and Institutional Shares will vary.