Abstract This paper provides evidence that “illusory correlations”—a well-documented source of cognitive bias—lead some agents to be imperfectly rational noise traders. We focus on the head-and-shoulders chart pattern, considered by technical analysts to provide one of the most reliable trading signals. Our findings indicate that the pattern is associated with a substantial rise in trading volume even though it does not profitably predict directional movements. We further substantiate the connection between head-and-shoulders trading and imperfectly rational noise trading by showing that the pattern is associated with lower bid-ask spreads.

Abstract Close to 30% of the US population experiences at least one mental or substance abuse disorder each year. Given the prevalence of mental health issues, this paper analyzes the role of mental health and cognitive functioning in household portfolio choice decisions. Generally, we find that households affected by mental health issues decrease investments in risky instruments. Various mental health issues can reduce the probability of holding risky assets by up to 19%. Moreover, single women diagnosed with psychological disorders increase investments in safe assets. We also find that cognitive functioning issues are associated with an increase in financial assets devoted to retirement accounts.