We show that stock prices are more accurate when short sellers are more active. First, in a large panel of NYSE-listed stocks, intraday informational efficiency of prices improves with greater shorting flow. Second, at monthly and annual horizons, more shorting flow accelerates the incorporation...

We study the effect of algorithmic trading (AT) on market quality between 2001 and 2011 in 42 equity markets around the world. We use exchange co-location service that increases AT as an exogenous instrument to draw causal inferences of AT on market quality. On average, AT improves liquidity and...

We provide new evidence on the relation between order flow and prices, an issue that is central to asset pricing and market microstructure. We examine proprietary data on a broad panel of NYSE-listed stocks that reveal daily order imbalances by institutions, individuals, and market makers. We...

Using NYSE short-sale order data, we investigate whether short-sellers' informational advantage is related to firm earnings and analyst-related events. With a novel decomposition method, we find that while these fundamental event days constitute only 12% of sample days, they account for over 24%...