Russell 3000 Index

The Russell 3000 Index is a capitalization-weighted , maintained by FTSE Russell, that seeks to be a benchmark of the entire . It measures the performance of the 3,000 largest publicly held companies incorporated in America as measured by total market capitalization, and represents approximately 98% of the American public equity market. As of 31 March 2017^[update], the stocks of the Russell 3000 Index have a weighted average market capitalization of almost $140 billion; the median market capitalization is nearly $1.7 billion. The index, which was launched on January 1, 1984, is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group.

The ticker symbol on most systems is ^RUA.

The Russell 3000 Index is tracked by several exchange-traded funds, such as the iShares Russell 3000 ETF (NYSE Arca: IWV) and the Vanguard Russell 3000 ETF (NASDAQ: VTHR).

(as of March 31, 2017)

...
Wikipedia