In a financial market, some traders make decisions based on their own information, ignoring what prices reveal about others' information. These traders, called "cursed traders," rely too much on their own signals, leading to prices being less influenced by private signals and more by public signals. Markets with cursed traders see more trading activity than those with rational traders. When mixed, rational traders exploit cursed traders using momentum-trading strategies. As markets grow, cursed traders increase trading volume, unlike overconfidence models where volume decreases.