There are three principal phases of a bull market: the first is represented by reviving confidence in the future of business; the second is the response of stock prices to the known improvement in corporate earnings, and the third is the period when speculation is rampant – a period when stocks are advanced on hopes and expectations.

There are three principal phases of a bear market: the first represents the abandonment of the hopes upon which stocks were purchased at inflated prices; the second reflects selling due to decreased business and earnings, and the third is caused by distress selling of sound securities, regardless of their value, by those who must find a cash market for at least a portion of their assets.
– Robert Rhea, The Dow Theory, 1932

Charles Dow once wrote, "To know values is to know the meaning of the market." That quote may surprise trend-followers and adherents of technical analysis, because Dow's work is often squeezed into a caricature focusing on nothing more than confirmation and divergence across the Dow Jones Industrial and Transportation averages.