Shorting flows, public disclosure, and market efficiency

Abstract

Shorting flows remain a significant predictor of negative future stock returns during 2010–2015, when daily short-sale volume data are published in real time. This predictability decays slowly and lasts for a year. Long-term shorting flows are more informative than short-term shorting flows. Indeed, abnormal short-term shorting flows do not predict future returns or anticipate bad news. We find that short sellers exploit prominent anomalies. A comparison with the Regulation SHO data indicates that the predictability is much shorter-term during 2005–2007. Short sellers appear to have shifted from trading on short-term private information to trading on long-term public information that is gradually incorporated into prices.