Surprise in Short Interest

We extract the news component of short-selling activity by accounting for important cross-sectional, distributional differences in short interest. The resulting measure of surprise in short interest negatively predicts the cross section of both U.S. and international equity returns. Our results also indicate that this predictability originates from short sellers' informed trading on mispricing and the market's underreaction to the news component of short-sale reports. Consistent with the notion of costly arbitrage, the return predictability is stronger among illiquid, volatile stocks and stocks with high information uncertainty, but importantly, unrelated short-selling frictions.