iShares Russell 2500 ETF(CBOE:SMMD)

SMMD provides exposure to the 2,500 smallest companies in the total-market Russell 3000 Index, extending well into the micro-cap space. Underlying liquidity can be an issue in the small- and micro-cap space during extraordinary market events. SMMD should appeal to investors wishing to own the entire US market, less the 500 largest names. Investors looking for a complement to an existing large-cap position should be aware that each index provider uses different screening and rebalancing processes, so pairing SMMD with a fund tracking a non-Russell index (such as the S&P 500) will result in overlaps and omissions. It is important to look beyond a fund`s headline claims to understand its real exposure with respect to a particular market cap space.