Which U.S. market index tracks approximately 2,000 small-cap companies?

The Russell 2000 tracks approximately 2,000 small-cap companies in the United States. It is a widely followed benchmark for the small-cap segment of the U.S. equity market.

The index is part of the Russell indexes, which are constructed from the broader Russell 3000. The Russell 3000 is designed to represent roughly 98% of the investable U.S. equity market, while the Russell 2000 covers the smaller companies within that universe.

The Russell 2000 is market-capitalization weighted, so larger constituents generally have greater influence than smaller constituents. Its composition is reconstituted annually, a process that can cause substantial trading as companies enter, leave, or change weight.

It is different from the Nasdaq-100, which focuses on 100 large nonfinancial companies listed on Nasdaq, and from the Dow Jones Industrial Average, which contains 30 prominent U.S. companies. Investors often use the Russell 2000 to assess small-company performance.