Strategy. Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in common stocks of companies engaged, at the time of investment, in the research, development, production, or distribution of products or services related to health care, medicine, or the life sciences (collectively termed health sciences). While the fund may invest in companies of any size, the majority of its assets are expected to be invested in large- and mid-capitalization companies. The managers portfolio managers divide the health sciences sector into four main areas: pharmaceutical companies, health care services companies, medical products and devices providers, and biotechnology firms. Their allocation among these four areas will vary depending on the relative potential … Show more… Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in common stocks of companies engaged, at the time of investment, in the research, development, production, or distribution of products or services related to health care, medicine, or the life sciences (collectively termed health sciences). While the fund may invest in companies of any size, the majority of its assets are expected to be invested in large- and mid-capitalization companies. The managers portfolio managers divide the health sciences sector into four main areas: pharmaceutical companies, health care services companies, medical products and devices providers, and biotechnology firms. Their allocation among these four areas will vary depending on the relative potential within each area and the outlook for the overall health sciences sector. While most assets will be invested in U.S. common stocks, the fund may purchase other securities, including foreign securities, futures, and options in keeping with its investment objective. In addition, the fund writes call and put options primarily as a means of generating additional income. The fund reserves the right to use options to seek protection against a decline in the value of its securities or an increase in prices of securities that may be purchased. Normally, the fund will own the securities on which it writes these options. The premium income received by writing covered calls can help reduce but not eliminate portfolio volatility. The fund concentrates its investments (invests more than 25% of its total assets) in securities of companies in the health sciences sector, a comparatively narrow segment of the economy, and therefore may experience greater volatility than funds investing in a broader range of industries. In managing the fund, the manager uses a fundamental, bottom-up analysis that seeks to identify high quality companies and the most compelling investment opportunities. In general, the fund will follow a growth investment strategy, seeking companies whose earnings are expected to grow faster than inflation and the economy in general. When stock valuations seem unusually high, however, a value approach, which gives preference to seemingly undervalued companies, may also be emphasized. The fund generally seeks investments in companies that are developing new and effective medicines, as well as companies whose business models reduce costs or improve quality in health care systems. The fund may invest up to 35% of its total assets in foreign securities (including emerging market securities) and may have exposure to foreign currencies through its investment in these securities, its direct holdings of foreign currencies or through its use of foreign currency exchange contracts for the purchase or sale of a fixed quantity of a foreign currency at a future date. In pursuing its investment objective, the funds management has the discretion to purchase some securities that do not meet its normal investment criteria, as described above, when it perceives an unusual opportunity for gain. These special situations might arise when the funds management believes a security could increase in value for a variety of reasons including a change in management, an extraordinary corporate event, or a new product introduction or a favorable competitive development. The fund holds a certain portion of its assets in money market reserves which can consist of shares of the T. Rowe Price Government Reserve Fund (or any other internal T. Rowe Price money market fund) as well as U.S. dollar and foreign currency-denominated money market securities, including repurchase agreements, in the two highest rating categories, maturing in one year or less. The fund may sell securities for a variety of reasons such as to secure gains, limit losses or redeploy assets into more promising opportunities. Use of Hedging and Other Strategic Transactions . The fund is authorized to use all of the various investment strategies referred to under Additional Information About the Funds Principal Risks Hedging, derivatives and other strategic transactions risk including entering into option transactions. Show less