Jan. 28, 2019

BLACKROCK FUNDS^SM

BlackRock All-Cap Energy & Resources Portfolio

(the “Fund”)

Supplement dated August 1, 2019 to the Investor A, Investor C, Institutional and

Service Shares Summary Prospectuses and Prospectuses and the Statement of

Additional Information (“SAI”) of the Fund, each dated January 28, 2019

Effective immediately, BlackRock (as defined below) has agreed to: (i) lower contractual total operating expense caps for Investor A, Investor C, Institutional and Service Shares of the Fund; (ii) discontinue the voluntary expense caps for Investor A, Investor C, Institutional and Service Shares of the Fund; and (iii) extend the contractual fee waivers for the Fund’s Investor A, Investor C, Institutional and Service Shares. In addition, effective upon the closing of a reorganization with another BlackRock-advised fund that is expected to occur in the first quarter of 2020, the Fund will change its name to “BlackRock Energy Opportunities Fund.” Accordingly, effective immediately, the Fund’s Investor A, Investor C, Institutional and Service Shares Summary Prospectuses and Prospectuses and the SAI are amended as follows:

The section of the Investor A, Investor C and Institutional Shares Summary Prospectus and Prospectus entitled “Key Facts About BlackRock All-Cap Energy & Resources Portfolio — Fees and Expenses of the Fund” and “Fund Overview — Key Facts About BlackRock All-Cap Energy & Resources Portfolio — Fees and Expenses of the Fund” are deleted in their entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Advisors, LLC (“BlackRock”) or its affiliates. More information about these and other discounts is available from your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock and its affiliates) (each a “Financial Intermediary”) and in the “Details About the Share Classes” and the “Intermediary-Defined Sales Charge Waiver Policies” sections on pages 31 and A-1, respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page II-80 of Part II of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)	Investor A Shares			Investor C Shares			Institutional Shares
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)		5.25	%		None			None
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)		None	1		1.00	%2		None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)	Investor A Shares			Investor C Shares			Institutional Shares
Management Fee3		0.75	%		0.75	%		0.75	%
Distribution and/or Service (12b-1) Fees		0.25	%		1.00	%		None
Other Expenses		0.48	%		0.45	%		0.35	%
Total Annual Fund Operating Expenses		1.48	%		2.20	%		1.10	%
Fee Waivers and/or Expense Reimbursements3,4		(0.16	)%		(0.16	)%		(0.19	)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements3,4		1.32	%		2.04	%		0.91	%

¹  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 time of purchase as part of an investment of $1,000,000 or more.

²  There is no CDSC on Investor C Shares after one year.

³  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 47, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through January 31, 2021. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

⁴  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 47, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) as a percentage of average daily net assets to 1.32% (for Investor A Shares), 2.04% (for Investor C Shares), and 0.91% (for Institutional Shares) through January 31, 2021. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

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:

	1 Year		3 Years		5 Years		10 Years
Investor A Shares	$	652	$	953	$	1,276	$	2,188
Investor C Shares	$	307	$	673	$	1,165	$	2,521
Institutional Shares	$	93	$	331	$	588	$	1,323

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

	1 Year		3 Years		5 Years		10 Years
Investor C Shares	$	207	$	673	$	1,165	$	2,521

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 37% of the average value of its portfolio.

The section of the Service Shares Summary Prospectus and Prospectus entitled “Key Facts About BlackRock All-Cap Energy & Resources Portfolio — Fees and Expenses of the Fund” and “Fund Overview — Key Facts About BlackRock All-Cap Energy & Resources Portfolio — Fees and Expenses of the Fund” are deleted in their entirety and replaced with the following:

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Service Shares of All-Cap Energy & Resources.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)	Service Shares
Management Fee1		0.75	%
Distribution and/or Service (12b-1) Fees		0.25	%
Other Expenses		0.36	%
Total Annual Fund Operating Expenses		1.36	%
Fee Waivers and/or Expense Reimbursements1,2		(0.04	)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements1,2		1.32	%

¹  As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 27, BlackRock Advisors, LLC (“BlackRock”) has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through January 31, 2021. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

²  As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 27, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 1.32% of average daily net assets through January 31, 2021. The Fund may have to repay some of these waivers and/or reimbursements to BlackRock in the following two years. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

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:

	1 Year		3 Years		5 Years		10 Years
Service Shares	$	134	$	427	$	741	$	1,632

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 37% of the average value of its portfolio.