[macmccann]

This is the definition of the gambler's fallacy. However, if you look at a chart of the stock market vs. a chart of a coin being flipped many times, they will look very different. While a coin being flipped will either asymptotically trend towards zero or a positive slope of .5 depending upon how it is charted, the stock market will have large peaks and valleys, meaning that after a period of high growth (overvaluation), the market will not continue to value these stocks at a steady growth of 10% per year. Instead, the market will correct the value of these stocks, which looks like a short term undervaluation and so we should expect "more tails than usual".

[tarsinge]

I recommend you look at the random walk hypothesis, the chart (not the average) of a coin flipped does not trend towards 0 and looks surprisingly similar to stock charts