What is the Wilshire 5000 Stock Index?

The Wilshire 5000 is a stock index that tracks most publicly traded U.S. stocks on the Nasdaq, New York and American exchanges, according to The Motley Fool. As of 2015, it includes public stocks for more than 6,000 companies and is the world’s largest stock index by market value.

The Wilshire 5000 was founded in 1974 to reflect the entire U.S. stock market and is also called the Total Stock Market Index, though it excludes penny stocks and extremely small companies, explains The Motley Crew. Because the 500 largest companies by market capitalization compose over 70 percent of the index, as of 2015, and the index is market-capitalization weighted, large companies heavily influence the index's value.