Traditional index funds track a market index - hence the name. That may be the S&P 500 or NASDAQ or a smaller segment of the market. Non-traditional index funds, on the other hands, track customized index in order to achieve greater performance than their traditional counterparts. Non-traditional funds may also use leverage, such that they return a multiple of one of these customized indexes, thus ratcheting up potential returns (and potential losses) to an even greater extent.