We find a strong positive link between past IPO returns and future subscriptions at the investor level in Finland. Our setting allows us to trace this effect to the returns personally experienced by investors; the effect is not explained by patterns related to the IPO cycle, or wealth effects. This behavior is consistent with reinforcement learning, where personally experienced outcomes are overweighted compared to rational Bayesian learning. The results provide a microfoundation for the argument that investor sentiment drives IPO demand. The paper also contributes to understanding how popular investment styles develop, and has implications for the marketing of financial products.

This study documents patterns of investor behavior around Finnish rights issues. We find that shareholders of issuing companies lost at least €9.9 million in aggregate from 1995 to 2002 by exercising rights too early, selling rights in the open market below their intrinsic value, or leaving rights unexercised. At the investor level, the losses are modest. For example, the median household investor suffered a loss of €135 from not exercising or selling the rights. Investors with small portfolios, inactive trading history, those who know neither of the official languages in Finland, or who are living abroad leave money on the table the most.

We show that investors tend to hold the same securities as their parents. This intergenerational correlation is stronger for mothers and family members who are more likely to communicate with each other. An instrumental variables estimation and a natural experiment suggest that the correlation reflects social influence. This influence runs not only from parents to children, but also vice versa. The resulting holdings of identical securities increase intergenerational correlations in portfolio choice, exacerbate wealth inequality, and amplify the consequences of behavioral biases.

We trace the impact of formative experiences on portfolio choice. Plausibly exogenous variation in workers’ exposure to a depression allows us to identify the effects and a new estimation approach makes addressing wealth and income effects possible. We find that adversely affected workers are less likely to invest in risky assets. This result is robust to a number of control variables and it holds for individuals whose income, employment, and wealth were unaffected. The effects travel through social networks: individuals whose neighbors and family members experienced adverse circumstances also avoid risky investments.