T. Rowe Price New Horizons Fund, Inc.

T. Rowe Price

New Horizons Fund

Investor Class

I Class

SUMMARY

Investment Objective

The fund seeks long-term capital growth by investing primarily in common stocks of small, rapidly growing companies.

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

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - T. Rowe Price New Horizons Fund, Inc. - USD ($)	Investor Class		I Class
Maximum account fee	$ 20	[1]

Annual fund operating expenses
(expenses that you pay each year as a
percentage of the value of your investment)

Annual Fund Operating Expenses - T. Rowe Price New Horizons Fund, Inc.	Investor Class	I Class
Management fees	0.64%	0.64%
Distribution and service (12b-1) fees
Other expenses	0.14%	0.01%
Total annual fund operating expenses	0.78%	0.65%

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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example - T. Rowe Price New Horizons Fund, Inc. - USD ($)	1 year	3 years	5 years	10 years
Investor Class	80	249	433	966
I Class	66	208	362	810

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 38.8% of the average value of its portfolio.

Investments, Risks, and Performance

Principal Investment Strategies

The fund invests primarily in a diversified group of small, emerging growth companies, preferably early in their corporate life cycle before the companies become widely recognized by the investment community. The fund may also invest in companies that offer the possibility of accelerating earnings growth because of rejuvenated management, new products, or structural changes in the economy. The portfolio manager will not necessarily sell a position in a company that has grown beyond the developing stage if the company still fits the fund’s other investment criteria. The fund may at times invest significantly in certain sectors, such as the information technology sector.

When choosing stocks for the fund’s portfolio, T. Rowe Price analysts tend to look for small growth companies that exhibit some or all of the following characteristics:

• effective management;

• operate in fertile growth areas;

• demonstrate innovative research, product development, and marketing;

• provide efficient service;

• possess pricing flexibility; and

• employ sound financial and accounting policies.

In pursuing its investment objective, the fund has the discretion to deviate from its normal investment criteria. These situations might arise when the fund’s adviser believes a security could increase in value for a variety of reasons, including an extraordinary corporate event, a new product introduction or innovation, a favorable competitive development, or a change in management.

The fund’s investments may include holdings in privately held companies and companies that only recently began to trade publicly. The fund may at times invest significantly in securities issued by technology companies. While most assets will typically be invested in U.S. common stocks, the fund may invest in foreign stocks in keeping with the fund’s objective.

The fund may sell securities for a variety of reasons, such as to secure gains, limit losses, or redeploy assets into more promising opportunities.

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:

Active management risks The investment adviser’s judgments about the attractiveness, value, or potential appreciation of the fund’s investments may prove to be incorrect. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies if the fund’s overall investment selections or strategies fail to produce the intended results.

Risks of 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 stock market or because of factors that affect a particular company or industry.

Small-cap stock risks Investing primarily in issuers within the same market capitalization category carries the risk that the category may be out of favor due to current market conditions or investor sentiment. Because the fund invests primarily in securities issued by small-cap companies, it is likely to be more volatile than a fund that focuses on securities issued by larger companies. Small-sized companies often have less experienced management, narrower product lines, more limited financial resources, and less publicly available information than larger companies. In addition, smaller companies are typically more sensitive to changes in overall economic conditions and their securities may be difficult to trade.

Private placement/IPO risks Any investments in the stocks of privately held companies and newly public companies involve greater risks than investments in stocks of companies that have traded publicly on an exchange for extended time periods. There is significantly less information available about these companies’ business models, quality of management, earnings growth potential, and other criteria that are normally considered when evaluating the investment prospects of a company. Private placements and other restricted securities held by the fund are generally considered to be illiquid and are difficult to value since there are no market prices and less overall financial information available. The adviser evaluates a variety of factors when assigning a value to these holdings, but the determination involves some degree of subjectivity and the value assigned for the fund may differ from the value assigned by other mutual funds holding the same security.

Investment style risks Different investment styles tend to shift in and out of favor depending on market conditions and investor sentiment. The fund’s growth approach to investing could cause it to underperform other stock funds that employ a different investment style. Growth stocks tend to be more volatile than certain other types of stocks, and their prices may fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings and may lack dividends that can help cushion its share price in a declining market.

Sector concentration risks At times, the fund may have a significant portion of its assets invested in securities of companies conducting business in a broadly related group of industries within an economic sector. Companies in the same economic sector may be similarly affected by economic or market events, making the fund more vulnerable to unfavorable developments in that economic sector than funds that invest more broadly. For example, the fund may have a significant portion of its assets invested in securities of companies in the in the information technology sector. Companies in the information technology sector can be adversely affected by, among other things, intense competition, earnings disappointments, and rapid obsolescence of products and services due to technological innovations or changing consumer preferences.

Foreign investing risks The fund’s investments in foreign securities may be adversely affected by local, political, social, and economic conditions overseas, greater volatility, reduced liquidity, or decreases in foreign currency values relative to the U.S. dollar. These risks are heightened for the fund’s investments in emerging markets, which are more susceptible to governmental interference, less efficient trading markets, and the imposition of local taxes or restrictions on gaining access to sales proceeds for foreign investors.

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.

New Horizons Fund
Calendar Year Returns

	Quarter Ended	Total Return		Quarter Ended	Total Return
Best Quarter	6/30/09	20.25%	Worst Quarter	12/31/08	-25.97%

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 an IRA. 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, 2017

Average Annual Total Returns - T. Rowe Price New Horizons Fund, Inc.	1 Year	5 Years	10 Years	Since inception		Inception date
Investor Class	31.49%	18.57%	13.16%			Jun. 03, 1960
Investor Class | Returns after taxes on distributions	28.73%	16.34%	11.58%			Jun. 03, 1960
Investor Class | Returns after taxes on distributions and sale of fund shares	19.43%	14.56%	10.60%			Jun. 03, 1960
I Class	31.67%			16.24%		Aug. 28, 2015
Russell 2000 Growth Index (reflects no deduction for fees, expenses, or taxes)	22.17%	15.21%	9.19%	12.51%	[1]	Aug. 28, 2015
S&P 500 Index (reflects no deduction for fees, expenses, or taxes)	21.83%	15.79%	8.50%	15.88%	[1]	Aug. 28, 2015
Lipper Mid-Cap Growth Funds Index	25.90%	14.31%	7.71%	12.21%	[1]	Aug. 28, 2015

Updated performance information is available through troweprice.com.

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

[1] Return as of 8/28/15.