Behavior gap refers to the difference between the actual return earned by an investor and the return that he could have earned if he had invested more conservatively in the broader market. The gap is attributed to the investor’s behavioural mistakes which cause him to under perform the market index. An investor who tries to outperform the market average by picking individual stocks, for instance, might take emotional decisions that lead to returns that are lower than the market average. The term was coined by American investor Carl Richards in his book in 2012.