IWR tracks the Russell Midcap Index, which holds the smaller part of the Russell 1000, roughly the 200th to 1,000th largest US companies by market capitalization. Mid-caps are more established than small caps and have more room to grow than the largest companies. The sector mix is more balanced than in large-cap indexes, with larger weights in industrials, financials, technology and consumer companies. The fund is cap-weighted and its holdings are reconstituted annually.
