The Russell 3000 Index is a capitalization-weighted stock market index that seeks to be a benchmark of the entire U.S. stock market. It measures the performance of the 3,000 largest publicly held companies incorporated in America as measured by total market capitalization, and represents approximately 97% of the American public equity market. The index was launched on January 1, 1984, and is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group. The ticker symbol on most systems is ^RUA. Wikipedia