The fund invests at least 80% of its assets in the securities of the index. The index is comprised of a subset of the companies within the Russell 1000® Index. The index was designed to reflect the performance of U.S. large- and mid-cap growth and value companies through the application of a rules-based methodology, which typically results in approximately 325-400 Index holdings, but this range can fluctuate because the index has no constraints on number of holdings.