A Major Shift Could Drive Stocks in Coming Years

 | Mar 21, 2012 04:58AM ET

Many investors have been surprised by the steady advances in the stock market since it bottomed out three years ago. They shouldn't have been. History predicted it would happen.

Exiting a major economic slowdown, companies cut costs fairly quickly, leading to a tremendous spike in profit margins. Consider this statistic: Companies in the S&P 500 boosted per-share profits by 38% in 2010, with roughly 80% of that coming from margin gains. Sales growth accounted for the remainder.