The Russell 2000 Index is a stock market index that measures the performance of approximately 2,000 smaller companies included in the Russell 3000 Index. The index was launched in 1984 by the Frank Russell Company and is now managed by FTSE Russell. The index is frequently used as a benchmark for measuring the performance of small-cap mutual funds. The Russell 2000 is a market-capitalization weighted index, which means that the amount that each company accounts for in the index is determined by the size of the company’s market cap, or the total value of its shares outstanding. The indexs returns can be replicated by investors who take the trouble to create a sizeable and complex portfolio that mirrors the index. However, there are far easier ways to get the same returns. For instance, investors can use index futures or index-based mutual funds that track the Russell 2000. The most popular option is an ETF. The most heavily traded of the ETFs is the iShares Russell 2000 index ETF (IWM). Although you cannot invest directly in the Russell 2000 Index, you can invest in mutual funds and ETFs that track the index.