This is a momentum buy and hold strategy using Industry Groups.

Basically it’s Buy/Long when the S&P is above the 300 day SMA and Sell/Short when the S&P is below the 300 day SMA – Rebalance every month.  In the Long position, one should hold the top three Industry Groups.  As of this writing, the S&P is above the 300 day SMA, but is getting hit bad; and the top three groups are Services, Technology and Conglomerates.   

http://stockcharts.com/school/doku.php?id=chart_school:trading_strategies:sector_rotation_roc