SUMMARY PROSPECTUS
PREIX PRUIX	Investor Class I Class
May 1, 2017
T. Rowe Price Equity Index 500 Fund
An index fund seeking to match the performance of the S&P 500, an index consisting of primarily large-cap U.S. stocks.
Before you invest, you may want to review the fund’s prospectus, which contains more information about the fund and its risks. You can find the fund’s prospectus and other information about the fund online at troweprice.com/prospectus. You can also get this information at no cost by calling 1-800-638-5660, by sending an e-mail request to info@troweprice.com, or by contacting your financial intermediary. This Summary Prospectus incorporates by reference the fund’s prospectus, dated May 1, 2017, as amended or supplemented, and Statement of Additional Information, dated May 1, 2017, as amended or supplemented. The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Summary 1

Investment Objective

The fund seeks to track the performance of a benchmark index that measures the investment return of large-capitalization U.S. stocks.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the fund. You may also incur brokerage commissions and other charges when buying or selling shares of the fund, which are not reflected in the table.

Fees and Expenses of the Fund

	Investor Class		I Class
Shareholder fees (fees paid directly from your investment)
Redemption fee (as a percentage of amount redeemed on shares held for 90 days or less)	0.50	%	0.50	%
Maximum account fee	$20	a	—
Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Management fees	0.10	%	0.10	%
Distribution and service (12b-1) fees	—		—
Other expenses	0.17		—
Total annual fund operating expenses	0.27		0.10
Fee waiver/expense reimbursement	(0.02	)b,c	—
Total annual fund operating expenses after fee waiver/expense reimbursement	0.25	b,c	0.10

aSubject to certain exceptions, accounts with a balance of less than $10,000 are charged an annual $20 fee.

bRestated to reflect current fees.

cT. Rowe Price Associates, Inc., has agreed (through April 30, 2019) to waive its fees and/or bear any expenses (excluding interest; expenses related to borrowings, taxes and brokerage; extraordinary expenses; and acquired fund fees and expenses) that would cause the class’ ratio of expenses to average daily net assets to exceed 0.25%. The agreement may be terminated at any time beyond April 30, 2019, with approval by the fund’s Board of Directors. Fees waived and expenses paid under this agreement (and a previous limitation of 0.30%) are subject to reimbursement to T. Rowe Price Associates, Inc., by the fund whenever the class’ expense ratio is below 0.25%. However, no reimbursement will be made more than three years after the waiver or payment, or if it would result in the expense ratio exceeding 0.25% (excluding interest; expenses related to borrowings, taxes and brokerage; extraordinary expenses; and acquired fund fees and expenses).

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, that your investment has a 5% return each year, and that the fund’s operating expenses remain the same. The example also assumes that an expense limitation currently in place is not renewed; therefore, the figures have been adjusted to reflect fee waivers or expense reimbursements only in the

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periods for which the expense limitation arrangement is expected to continue. 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 Class	$26	$85	$150	$341
I Class	10	32	57	128

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 the fund’s 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 8.6% of the average value of its portfolio.

Investments, Risks, and Performance

Principal Investment Strategies The fund attempts to match the investment return of large-capitalization U.S. stocks by seeking to match the performance of its benchmark index, the S&P 500 Index. The fund uses a full replication strategy, which involves investing substantially all of its assets in all of the stocks in the S&P 500 and seeking to maintain holdings of each stock in proportion to its weight in the index.

The S&P 500 is made up of primarily large-capitalization companies that represent a broad spectrum of the U.S. economy and a substantial part of the U.S. stock market’s total capitalization. (Market capitalization is the number of a company’s outstanding shares multiplied by the market price per share.)

S&P Dow Jones Indices LLC (“SPDJI”) constructs the benchmark index by first identifying major industry categories and then allocating a representative sample of the larger and more liquid stocks in those industries to the index. SPDJI weights each stock according to its total market value. For example, the 50 largest companies in the index may account for over 50% of its value.

Under normal conditions, the fund will invest at least 80% of its net assets (including any borrowings for investment purposes) in stocks that are included in its benchmark index. T. Rowe Price compares the composition of the fund to that of the index. If a material misweighting develops, the portfolio manager seeks to rebalance the portfolio in an effort to realign it with its index.

While most assets will be invested in common stocks, the fund may also purchase stock index futures contracts. Futures would typically be used to reduce cash balances in the fund and increase the level of fund assets exposed to common stocks represented in the fund’s benchmark index. In addition, the fund lends its portfolio securities as a means of generating additional income.

Summary 3

While there is no guarantee, the correlation between the fund and its benchmark index is expected to be at least 0.95. A correlation of 1.00 indicates that the returns of the fund and the index will always move in the same direction (but not necessarily by the same amount). A correlation of 0.00 would mean price movements in the fund are unrelated to price movements in the index.

The fund may sell securities to better align its portfolio with the characteristics of its benchmark index or to satisfy redemption requests. The fund will generally seek to sell securities that have been removed from the benchmark index within a reasonable timeframe taking into consideration market conditions.

Principal Risks As with any mutual fund, there is no guarantee that the fund will achieve its objective. The fund’s share price fluctuates, which means you could lose money by investing in the fund. The principal risks of investing in this fund are summarized as follows:

Risks of U.S. stock investing Stocks generally fluctuate in value more than bonds and may decline significantly over short time periods. There is a chance that stock prices overall will decline because stock markets tend to move in cycles, with periods of rising and falling prices. The value of a stock in which the fund invests may decline due to general weakness in the U.S. stock market, such as when the U.S. financial markets decline, or because of factors that affect a particular company or industry.

Market capitalization risks Although stocks issued by larger companies tend to have less overall volatility than stocks issued by smaller companies, larger companies may not be able to attain the high growth rates of successful smaller companies, especially during strong economic periods. In addition, larger companies may be less capable of responding quickly to competitive challenges and industry changes, and may suffer sharper price declines as a result of earnings disappointments.

Index investing risks Because the fund is passively managed and seeks to match the performance of its benchmark index, holdings are generally not reallocated based on changes in market conditions or outlook for a specific security, industry, or market sector. As a result, the fund’s performance may lag the performance of actively managed funds.

Tracking error The returns of the fund are expected to be slightly below the returns of its benchmark index (referred to as “tracking error”) because the fund incurs fees and transaction expenses while the index has no fees or expenses. The risk of tracking error is increased to the extent the fund is unable to fully replicate its benchmark index, which could result from changes in the composition of the index or the timing of purchases and redemptions of fund shares.

Futures risks The fund’s use of stock index futures exposes it to potential volatility and losses in excess of direct investments in the contract’s underlying assets. The values of the fund’s positions in stock index futures tend to fluctuate in response to changes in the value of the underlying index, which exposes the fund to the risk that

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the underlying index will not move in a direction that is favorable to the fund. While the value of a stock index futures contract tends to correlate with the value of the underlying index, differences between the futures market and the value of the underlying index may result in an imperfect correlation. Since losses could result from market movement, the fund may need to sell other portfolio securities at disadvantageous times in order to meet daily margin requirements. The futures markets may experience reduced liquidity, which could result in losses to the fund and cause the fund to be unable to settle its futures positions.

Securities lending risks Securities lending involves the risk that the fund may lose money because the borrower of the loaned securities fails to return the securities to the fund in a timely manner or not at all. The fund may also lose money if there is a decline in the value of the collateral provided for loaned securities or a decline in the value of any investments made with cash collateral. In addition, securities lending activities may cause adverse tax consequences for the fund.

Performance The following performance information provides some indication of the risks of investing in the fund. The fund’s performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results.

The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses.

Summary 5

The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year, and also compares the returns with the returns of a relevant broad-based market index, as well as with the returns of one or more comparative indexes that have investment characteristics similar to those of the fund.

In addition, the table shows hypothetical after-tax returns to demonstrate how taxes paid by a shareholder may influence 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 an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or individual retirement account. After-tax returns are shown only for the Investor Class and will differ for other share classes.

Average Annual Total Returns
			Periods ended
			December 31, 2016
									Since		Inception
			1 Year		5 Years		10 Years		inception		date
	Investor Class										03/30/1990
		Returns before taxes	11.70	%	14.36	%	6.69	%	—	%
		Returns after taxes on distributions	11.14		13.87		6.32		—
		Returns after taxes on distributions
		and sale of fund shares	7.04		11.51		5.37		—
	I Class										08/28/2015
		Returns before taxes	11.87		—		—		11.52
	S&P 500 Index (reflects no deduction for fees, expenses, or taxes)		11.96		14.66		6.95		11.64	a

aReturn as of 8/28/15.

Updated performance information is available through troweprice.com.

Management

Investment Adviser T. Rowe Price Associates, Inc. (T. Rowe Price)

Portfolio Manager	Title	Managed Fund Since	Joined Investment Adviser
Ken D. Uematsu	Chairman of Investment Advisory Committee	2008	1997

Purchase and Sale of Fund Shares

The fund generally requires a $2,500 minimum initial investment ($1,000 minimum initial investment if opening an IRA, a custodial account for a minor, or a small business retirement plan account). Additional purchases generally require a $100

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minimum. These investment minimums may be waived or modified for financial intermediaries and certain employer-sponsored retirement plans submitting orders on behalf of their customers.

The I Class generally requires a $1,000,000 minimum initial investment and there is no minimum for additional purchases, although the initial investment minimum may be waived for intermediaries and retirement plans maintaining omnibus accounts, and certain institutional client accounts for which T. Rowe Price or its affiliate has discretionary investment authority.

For investors holding shares of the fund directly with T. Rowe Price, you may purchase, redeem, or exchange fund shares by mail; by telephone (1-800-225-5132 for IRAs and nonretirement accounts; 1-800-492-7670 for small business retirement plans; and 1-800-638-8790 for institutional investors and financial intermediaries); or, for certain accounts, by accessing your account online through troweprice.com.

If you hold shares through a financial intermediary or retirement plan, you must purchase, redeem, and exchange shares of the fund through your intermediary or retirement plan. You should check with your intermediary or retirement plan to determine the investment minimums that apply to your account.

Tax Information

Any dividends are declared and paid quarterly in March, June, September, and December. Any capital gains are declared and paid annually, usually in December. Redemptions or exchanges of fund shares and distributions by the fund, whether or not you reinvest these amounts in additional fund shares, may be taxed as ordinary income or capital gains unless you invest through a tax-deferred account (in which case you will be taxed upon withdrawal from such account).

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of the fund through a broker-dealer or other financial intermediary (such as a bank), the fund and its related companies may pay the intermediary for the sale of fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information. However, the fund and its investment adviser do not pay broker-dealers and other financial intermediaries for sales or related services of the I Class shares.

T. Rowe Price Associates, Inc.
100 East Pratt Street
Baltimore, MD 21202 F50-045 5/1/17