We find a strong positive link between past IPO returns and future subscriptions at the investor level in Finland. Our setting allows tracing 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, in which 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.

Peer performance can influence the adoption of financial innovations and investment styles. We present empirical evidence of this type of social influence: recent stock market returns that local peers experience strongly influence an individual's stock market entry decision. This effect is limited to positive returns that encourage entry, whereas negative returns do not make entry less likely. Market returns, media coverage, returns on locally held stocks, omitted local variables, and stock purchases within households do not drive our results. This type of social influence may partly explain, among other things, why participation rates tend to sharply increase in times of high market returns.

This paper shows that prospect theory is unlikely to explain the disposition effect. Prospect theory predicts that the propensity to sell a stock declines as its price moves away from the purchase price in either direction. Trading data, on the other hand, show that the propensity to sell jumps at zero return, but it is approximately constant over a wide range of losses and increasing or constant over a wide range of gains. Further, the pattern of realized returns does not seem to stem from optimal after-tax portfolio rebalancing, a belief in mean-reverting returns, or investors acting on target prices.

"We use data from surveys involving 300 Scandinavian financial market professionals and 213 university students to conduct three controlled experiments in which we manipulate the background information given to subjects. We find a very large anchoring effect in the students' long-term stock return expectations, that is, their estimates are influenced by an initial starting value. Professionals show a much smaller anchoring effect, but it nevertheless remains statistically and economically significant, even when we restrict the sample to more experienced professionals. We also find that the professionals are not conscious of the impact of historical returns on their expectations." Copyright (c) 2008 Financial Management Association International..

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