“Once a bull market gets underway and once you reach the point where everybody has made money no matter what system he or she followed, a crowd is attracted into the game that is responding not to interest rates and profits but simply to the fact that it seems a mistake be out of stocks. In effect, these people superimpose an I-can’t-miss-the-party factor on top of the fundamental factors that drive the market. Like Pavlov’s dog, these “investors” learn that when the bell rings – in this case, the one that opens the New York Stock Exchange at 9:30 AM – they get fed. Through this daily reinforcement, they become convinced that there is a God and that He wants them to get rich.”

– Warren Buffett, November 1999