Warren Buffett: We simply attempt to be fearful when others are greedy and to be greedy only when others are fearful.

What we do know, however, is that occasional outbreaks of those two super-contagious diseases, fear and greed, will forever occur.  The timing of these epidemics will be unpredictable.  And the market aberrations produced by them will be equally unpredictable, both as to duration and degree.  Therefore, we never try to anticipate the arrival or departure of either disease.  Our goal is more modest: we simply attempt to be fearful when others are greedy and to be greedy only when others are fearful.

As this is written, little fear is visible in Wall Street.  Instead, euphoria prevails - and why not?  What could be more exhilarating than to participate in a bull market in which the rewards to owners of businesses become gloriously uncoupled from the plodding performances of the businesses themselves. However, stocks can’t outperform businesses indefinitely.