The fund normally invests at least 80% of its net assets in equity securities of companies included in the S&P MidCap 400® Index. The S&P MidCap 400® Index includes approximately 400 stocks of mid-cap U.S. companies in a wide range of businesses. The adviser employs a "passive" management, or indexing, approach, which seeks to match approximately the performance of the S&P MidCap 400® Index before the deduction of fund expenses.