Billionaires Are Mostly Random

Falky mentioned a paper

"[L]ess informed investors earn the highest (and lowest) rates of return on their total portfolios because they irrationally believe they have a more favorable risk-return opportunity and hence invest in securities with a higher return. In effect, their ignorance effectively diminishes their risk aversion, and in the long run allows a lucky few of them to reap the financial rewards that would accrue to the less risk averse (one could call it the 'Forrest Gump' effect). As opposed to speculation weeding out the irrational traders and making only the best opinions matter, the irrational can dominate the class of winners."

Selection bias, like my review of How to be a Billionaire says.