ABSTRACT We find that option returns are significantly lower over nontrading periods, the vast majority of which are weekends. Our evidence suggests that nontrading returns cannot be explained by risk, but rather are the result of widespread and highly persistent option mispricing driven by the incorrect treatment of stock return variance during periods of market closure. The size of the effect implies that the broad spectrum of finance research involving option prices should account for nontrading effects. Our study further suggests how alternative industry practices could improve the efficiency of option markets in a meaningful way.

We study the value impact of environmental shareholder proposals (ESPs) for Russell 3000 firms from 2006 to 2021. We distinguish between climate-dedicated ESPs and non-climate ESPs covering other environmental topics. We use two approaches to evaluate management's ability and willingness to select value-enhancing ESPs and reject value-destroying ESPs: (i) cumulative abnormal returns around the final proxy filing date and (ii) a regression discontinuity design around the voting threshold at the annual general meeting. Our results suggest that management has screening ability for ESPs, especially for climate proposals, and that investors and managers share common objectives in environmental activism.