We find that short sale costs eliminate the abnormal profits generated by asset pricing anomalies. While many anomalies persist out-of-sample, they cannot be profitably exploited due to stock borrow fees. Using a comprehensive sample of 162 anomalies, we show that the average of these long-short...

We train a machine learning method on a class of informed trades to develop a new measure of informed trading, the Informed Trading Intensity (``ITI''). ITI increases before earnings, M&A, and news announcements, and has implications for return reversal and asset pricing. ITI is effective...