Strategy. The Fund mainly invests in common stocks of U.S. companies that the portfolio managers expect to have above-average growth rates. The Fund seeks to invest in newer companies or in more established companies that are in the early growth phase of their business cycle, which is typically marked by above-average growth rates. Under normal circumstances, the Fund will invest at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of mid-cap issuers, and in derivatives and other instruments that have economic characteristics similar to such securities. The Fund considers an issuer to be a mid-capitalization issuer if it has a market capitalization within the range of the market capitalizations of the issuers included in … Show more… The Fund mainly invests in common stocks of U.S. companies that the portfolio managers expect to have above-average growth rates. The Fund seeks to invest in newer companies or in more established companies that are in the early growth phase of their business cycle, which is typically marked by above-average growth rates. Under normal circumstances, the Fund will invest at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of mid-cap issuers, and in derivatives and other instruments that have economic characteristics similar to such securities. The Fund considers an issuer to be a mid-capitalization issuer if it has a market capitalization within the range of the market capitalizations of the issuers included in the Russell Midcap Growth Index during the most recent 11-month period (based on month-end data) plus the most recent data during the current month. This range is subject to change at any time due to market activity or changes in the composition of that index. The range of the Russell Midcap Growth Index is reconstituted annually to preserve its capitalization characteristics. The Fund may invest up to 20% of its net assets in companies in other market capitalization ranges. An issuers market capitalization is the value of its outstanding stock. The Fund invests primarily in U.S. companies but may also purchase securities of issuers in any country, including developed countries and emerging markets. The Fund has no limits on the amount of its assets that can be invested in foreign securities, but currently does not intend to invest substantially in such securities. In selecting investments for the Fund, the portfolio managers look for companies with high growth potential using a bottom-up stock selection process. The bottom-up approach focuses on fundamental analysis of individual issuers before considering the impact of overall economic, market or industry trends. This approach includes analysis of a companys financial statements and management structure and consideration of the companys operations, product development, and its industry position. The portfolio managers currently focus on what they believe to be high-growth companies that are characterized by industry leadership, market share growth, high caliber management teams, sustainable competitive advantages, and strong growth themes or new innovative products or services. The portfolio managers monitor individual issuers for changes in the factors above, which may trigger a decision to sell a security, but does not require a decision to do so. The factors considered by the portfolio managers may vary in particular cases and may change over time. Show less