Business Week recently reported that "All funds that track the Standard & Poor’s 500-stock index are not created equal.

The exchange-traded Rydex S&P Equal Weight Fund (RSP ) offered by Rydex Investments is an exception. Every stock in its portfolio carries the same weight. That makes the exchange-traded fund (ETF) different from most S&P 500 index funds, which are market-cap weighted, meaning the biggest companies account for a larger chunk of assets than smaller ones do."

RSP handsomely outperformed the S&P 500 in 2005 and YTD in 2006 as small and mid-cap stocks lead their large-cap counterparts.

Tom Lydon is member of the Rydex fund board.

The opinions and forecasts expressed herein are solely those of Tom Lydon, and may not actually come to pass. Mr. Lydon serves as an independent trustee of certain mutual funds and ETFs that are managed by Guggenheim Investments; however, any opinions or forecasts expressed herein are solely those of Mr. Lydon and not those of Guggenheim Funds, Guggenheim Investments, Guggenheim Specialized Products, LLC or any of their affiliates. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.