The iShares Russell 2000 ETF (Ticker: IWM) The Russell 2000 is composed of the smallest 2000 companies in the Russell 3000. Total market capitalization is determined by combining total outstanding shares times the market price as of May 31 for those eligible at annual reconstitution on the last Friday in June. Initial public offerings (IPOs) may be added quarterly. Deletions due to mergers and acquisitions are not replaced until the next reconstruction in June.