Small changes in human psychology tends to produce exaggerated and amplified changes in asset prices. In reality, if you see any of the blue chip in any given year, the fluctuation between the hilo is in excess of 35 to forty%. So what does this imply? That there are factors beyond fundamentals which are at work. We tend to be social animals seeking comfort in collective wisdom. And it is very difficult to be contrarian when the whole crowd is moving against you.