A portfolio of mutual funds, index funds and ETF-traded products that track a particular stock or a particular sector can be useful for a diversified portfolio.The most common ones are the iShares Russell 2000 Index Fund (IISS), which tracks the S&P 500 index (NYSEARCA:SPY) and the Russell 2000 MidCap 500 Index Fund, which tracks MidCap-S&…
