The Gambler's Fallacy

The tendency to believe in hot-and-cold streaks.

We tend to assume that individual random events are influenced by previous random events. We've all seen people win several rolls of the dice in roulette and have marveled at basketball players who shoot successfully in "streaks." Sportscasters say they have a "hot hand." This widely held belief is false. Scientists have found that the success of a previous throw only very slightly predicts a subsequent success or miss. A similar effect occurs for other types of random dispersions, including seeing streaks in stock market price fluctuations over time. This bias is also called "The Monte Carlo Bias" and "The Clustering Illusion."