This study investigates whether stock market returns are related to temperature. Research in psychology has shown that temperature significantly affects mood, and mood changes in turn cause behavioral changes. Evidence suggests that lower temperature can lead to aggression, while higher temperature can lead to both apathy and aggression. Aggression could result in more risk-taking while apathy could impede risk-taking. We therefore expect lower temperature to be related to higher stock returns and higher temperature to be related to higher or lower stock returns, depending on the trade-off between the two competing effects. We examine many stock markets world-wide and find a statistically significant, negative correlation between temperature and returns across the whole range of temperature. Apathy dominates aggression when temperature is high. The observed negative correlation is robust to alternative tests and retains its statistical significance after controlling for various known anomalies.

Existing research on executive stock options mainly focuses on total risk when studying risk incentives. In this study, we use a GARCH option pricing framework to show that the incentive effects of executive stock options depend on the composition of risk. Controlling for total risk, the value of executive stock options increases with systematic risk and this effect is stronger when the total risk is low. Thus, when firms grant standard or non-indexed options, CEOs will have incentives to increase systematic risk even when the total risk remains constant. In contrast, indexed options will provide CEOs with incentives to reduce systematic risk. We therefore conclude that an optimal mix of indexed and non-indexed option grants will provide CEOs with incentives to take the desired level of systematic risk.