What is Russell 3000 Index?

The Russell 3000 Index is a market-capitalization weighted equity index. The index was founded in and based in Britain but it is used to track the performance of the 3,000 largest publicly held U.S. stocks that make up 98% of the U.S. stock market. The Russell 3000 Index is made up of the large-cap Russell 1000 Index and the small-cap Russell 2000 index. The index launched on January 1st, 1984, and is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group (LSEG).