Once Burned, Twice Shy: How Naive Learning, Counterfactuals, and Regret Affect the Repurchase of Stocks Previously Sold

Investors' previous experiences with a stock affect their willingness to repurchase that stock. Using detailed trade data from two brokers, the authors document that investors are reluctant to repurchase stocks previously sold for a loss and stocks that have risen in price subsequent to a prior sale. The authors propose that this behavior reflects investors' emotional reactions to trading and their attempts to distance themselves from negative emotions (e.g., disappointment, regret). Investors are disappointed when they sell a stock for a loss and regret having ever purchased the stock; these negative emotions deter investors from later repurchasing stocks they sold for a loss. Having sold a stock, investors are disappointed if the stock continues to rise and regret having sold the stock in the first place; these negative emotions deter investors from repurchasing stocks that go up since being sold. Thus, investors engage in reinforcement learning by repurchasing stocks whose previous purchase resulted in positive emotions and avoiding stocks whose previous purchase resulted in negative emotions.