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...

We examine the relation between liquidity, volume, and volatility using a comprehensive sample of U.S. stocks in the post-decimalization period. For large stocks, effective spread and volume are positively related in the time series even after controlling for volatility, contrary to most...

We document new intraday trading patterns indicative of the key roles of endogenous trading responses of investors to variations in imperfectly-competitive liquidity provision. When measured in trade times of fixed dollar values, price impacts and volatility fall sharply from open to close, and...

We show that wholesalers internalize unbalanced amounts of retail order flow to provide liquidity to institutional investors. The Tick Size Pilot highlights how wholesaler incentives affect the magnitude and composition of internalized retail trade imbalances (Mroib, Boehmer et al.\ 2021). Large...

Do order flows in index derivatives play an informational role? Weekly index put order flow on the International Securities Exchange positively and robustly predicts weekly S&P 500 index returns. This result obtains mainly for net put buying and is stronger in high VIX periods and in periods...

We examine how informed traders trade in the option market around news announcements. We show that their profits depend on whether positions are long or short, whether trades take place before or after news releases, and whether events are scheduled or unscheduled. We predict and find that...