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 study the information content in monthly short interest using NYSE-, AMEX-, and NASDAQ-listed stocks from 1988 to 2005. We show that stocks with relatively high short interest subsequently experience negative abnormal returns, but the effect can be transient and of debatable economic...

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%...

Short sellers are known to have private information about security prices. Empirical evidence of short selling, however, is based on only half of short sellers' trading activity; specifically, the opening of the position. Using disclosed large short position data from the Japanese stock market,...

We examine product differentiation in the high-frequency trading (HFT) industry, where the “products” are secretive proprietary trading strategies. We demonstrate how principal component analysis can be used to detect underlying strategies that are common to multiple HFT firms, and show that...

The total effect of a regulatory change consists of direct effects and indirect effects (spillovers), but the standard difference-in-difference approach measures only direct effects and ignores potential indirect effects. By examining the short-sale aggressiveness during the 2007 full repeal of...