Asymmetric trading restriction and return comovement

This study decomposes the overall return comovement into intraday and overnight comovement based on a model-free framework. It shows that intraday return comovement contributes the most to the overall return comovement, but the impact of overnight return comovement is persistent. Investors under the market with asymmetric trading restrictions (ATR) tend to sell stocks early in the market and buy them near the end of the market. This correlated trading behavior contributes to the specific comovement in stock returns, especially the overnight return. Our findings remain solid even after controlling for more stock attributes and changing the proxies for return comovement and investor trading behavior. We also document a weakening (reinforcing) effect of the short-selling mechanism (disposition effect) on the ATR-induced return comovement. Our results provide a deeper understanding of investors’ trading behavior under ultra-short-term trading restrictions and the source of return comovement in the literature.