Are happy investors likely to be overconfident?

This study investigates the relationship of investors' happy sentiment and overconfidence effect. Sunshine, temperature, former returns, and margin loan change rate are used as proxies for happy sentiment. Using data from Taiwan Stock Exchange and principal component analysis, the happy sentiment index is divided into two categories: "natural environment happiness" and "investment atmosphere happiness." The results suggest that when natural environment happiness is stronger, investors are less likely to have overconfidence. On the contrary, when investment atmosphere happiness is stronger, investors are more likely to have overconfidence.