According to prospect theory [Kahneman, D., & Tversky, A. (1979). Prospect theory: An analysis of decision under risk, Eco- nometrica, 47, 263–292], gains and losses are measured from a reference point. We attempted to ascertain to what extent the refer- ence point shifts following gains or losses. In questionnaire studies, we asked subjects what stock price today will generate the same utility as a previous change in a stock price. From participants’ responses, we calculated the magnitude of reference point adapta- tion, which was significantly greater following a gain than following a loss of equivalent size. We also found the asymmetric adap- tation of gains and losses persisted when a stock was included within a portfolio rather than being considered individually. In studies using financial incentives within the BDM procedure [Becker, G. M., DeGroot, M. H., & Marschak, J. (1964). Measuring utility by a single-response sequential method. Behavioral Science, 9(3), 226–232], we again noted faster adaptation of the reference point to gains than losses. We related our findings to several aspects of asset pricing and investor behavior.

We study the effects of a direct high-speed rail (HSR) service between two cities on investors and firms in China’s A-share markets. After an HSR introduction, retail investors make more cross-city web searches and block stock purchases of firms in connected cities. An HSR introduction also leads to less comovement among local stocks and more comovement between stocks in connected cities. Firms located in more central cities in the HSR network enjoy higher firm valuation, lower cost of equity, higher turnover, and better liquidity, in part through the channel of increased investor recognition. The HSR effects on capital market outcomes are more pronounced among small firms and when the connected city-pair distance is below 1,500 km, for which HSR is faster than flying. The findings highlight the importance of in-person interactions in financial markets.

We examine how stakes affect investor behaviors. In our unique setting, the same investors trade stocks in real accounts using their own money and, at the same time, trade in a simulated setting. Our real-world within-investor estimation produces strong evidence that investors exhibit stronger biases and perform worse in their higher-stakes real accounts than in their lower-stakes simulated accounts. Even with no monetary stakes, investors exhibit strong biases in their simulated accounts, and biases in the two types of accounts are strongly positively correlated. Such behavioral consistency suggests that low-stakes experimental methods, although imperfect, can be informative about real-world human behaviors. Using account data from two brokerage companies, we find that investors exhibit a stronger disposition effect on positions with greater portfolio weight. Hence, the finding that stakes-strengthening-biases may not be unique to the comparison between no-monetary and high-monetary stakes.

We examine whether investor behavior can be influenced by the social norms to which they are exposed. Specifically, we test two competing hypotheses regarding the influence of social trust on the disposition effect related to mutual fund investment. On the one hand, a higher level of social trust may elicit stronger investor reactions by increasing the credibility of the performance numbers reported by funds. This results in higher flow-performance sensitivity, which mitigates investors’ tendency to sell winners and hold onto losers. On the other hand, societal trust may reduce concerns about expropriation, thereby weakening investors’ need to react to poor performance. The resulting lower flow-performance sensitivity increases the disposition effect. Based on a proprietary dataset of complete account-level trading information for all investors in a large mutual fund family in China, we find compelling evidence 1) of a significant disposition effect among fund investors; 2) that a higher degree of social trust is associated with higher flow-performance sensitivity; and 3) that (high) trust-induced flows mitigate the disposition effect. Our results suggest that, in addition to cognitive biases, investor behavior is also strongly influenced by social norms.

We study the effect of mutual fund allocation on China’s IPO market under the new registration system. The introduction of mutual fund bids significantly increases IPO offer price, resulting in a low initial short-term return and suppressed IPO underpricing. Those newly listed stocks witness lower volatility in the following weeks due to preferential allocation to the mutual fund at the primary market. Further analysis suggests that large investors tend to buy during the first week after IPO and their net purchase strengthens IPO after-market volatility. This new evidence suggests that mutual fund allocation plays a critical role in IPO price discovery and decreases investor lottery trading.

We analyze the possible effect of price limit to informed traders’ behavior and propose three hypotheses caused by price limit. Then comprehensively using the event study method and comparative grouping method, we empirically exams the performance of price limit in China’s stock market. Our finding is that price limit policy will bring significant effect to the trading behavior of insiders, which means price limit policy will impede the fulfillment of insiders’ trading activities and delay equilibrium price discovery.