The investment seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of the SSGA Total Stock Market Index that tracks a broad universe of exchange traded U.S. equity securities. The fund generally invests substantially all, but at least 80%, of its total assets in the securities comprising the index. It may invest in equity securities that are not included in the index (including common stock, preferred stock, depositary receipts and shares of other investment companies), cash and cash equivalents or money market instruments. The fund is non-diversified.