Here’s one of the many (many) reasons you (and Goldman Sachs) should never try to time the stock market:
March 21, 2012 Goldman Sachs Market Call to Clients (Dow at 13,125):
Goldman Sachs, in a sweeping report to clients Wednesday, said it is a once-in-a-lifetime opportunity to buy stocks, which the firm said are undervalued after 20 years of relative underperformance against bonds.