The Russell 1000, a subset of the Russell 3000, is a large-cap stock index consisting of the largest 1,000 publicly listed U.S. companies, ranked by market value. Despite the index having only a third of the stocks in the Russell 3000, which covers 96% of the U.S. investable stock market universe, it still offers a broad representation — 93% of the stock market. FTSE Russell, a wholly owned London Stock Exchange Group subsidiary, established the Russell 1000 on January 1, 1984.
The Russell 3000 is an equity index that tracks the largest 3,000 U.S. companies. It is market-capitalization weighted, meaning that each holding in the index receives a percentage size proportional to its total market cap. Overall, the index properly represents the broad market because it tracks 96% of the publicly listed U.S. equity market universe. It also has a diverse composition, holding a mix of large-caps, mid-caps, and small-caps.