The term Wilshire 2500 Index refers to a composite that includes large and small capitalization companies located in the United States. The Wilshire 2500 is published and maintained by Wilshire Associates.
The Wilshire 5000 Total Market Index is designed to measure the performance of the large, mid, small, and micro capitalization companies in the United States equities market. The index is a composite of all the securities (primary equity, common stock, REIT, or Limited Partnership) that have a primary market listing in the United States. The Wilshire 2500 Index consists of the companies in the Wilshire 5000 that rank in the top 2500 positions in terms of market capitalization.
First published in 1996, the index is rebalanced every six months. The Wilshire 2500 is a float-adjusted, market capitalization-weighted index. As defined by Wilshire, the 2500 is a composite of the Wilshire US Large Cap and Wilshire US Small Cap indexes.