How does the Russell 2000 index work?
The Russell 2000 is designed to provide the best indicator of the performance of small-cap U.S. stocks. To keep up to date on these stocks, the Russell 2000 is reconstituted annually to ensure that the companies in it represent the small-cap universe.
In simple terms, if a company grows too large, it will be removed from the Russell 2000. In turn, it will likely be placed in the Russell 1000, which is designed to be a barometer of large-cap stocks' performances.
As an example, GameStop (GME -1.20%) was added to the Russell 1000 in the 2021 reconstitution and removed from the Russell 2000 after its price soared in the meme stock craze. In all, 38 companies were added to the Russell 1000 in June 2024, with 27 moving from the Russell 2000.
Notably, one of the companies that departed the Russell 2000 during the 2024 reconstitution is Super Micro Computer (SMCI -5.04%). The stock left behind some big shoes to fill as it made its way into the Russell 1000 as the largest company by weight.