The Wilshire 5000 Total Market Index, or more simply the Wilshire 5000, is a market-capitalization-weighted index of the market value of all stocks actively traded in the United States. Currently, the index contains over 4,100 components.
The index is intended to measure the performance of most publicly traded companies headquartered in the United States, with readily available price data, (Bulletin Board/penny stocks and stocks of extremely small companies are excluded). Hence, the index includes a majority of the common stocks and REITs traded primarily through New York Stock Exchange, NASDAQ, or the American Stock Exchange. Limited Partnerships and ADRs are not included. It can be tracked by following the ticker W5000.
Additional meaning of Wilshire 5000:
The Wilshire 5000 Total Market Index was established by the Wilshire Associates in 1974, naming it for the approximate number of issues it included at the time. It was renamed the "Dow Jones Wilshire 5000" in April 2004, after Dow Jones & Company assumed responsibility for its calculation and maintenance. On March 31, 2009 the partnership with Dow Jones was concluded and the index returned to Wilshire Associates.