Suppose you have put your money in IT Sector and also have earned profit from it. But when that stock starts its downtrend, you did nothing but hold the shares which left you with a big loss. Now understand whenever any sector starts its bearish run simply book your profit and put your money to a new sector that just has come out from its negative returns to the positive one. Rotating your money from a bearish sector to a bullish sector is called Sectoral Rotation.