While algorithmic trading now dominates financial markets, some exchanges continue to use human floor traders. On March 23, 2020 the NYSE suspended floor trading because of COVID-19. Using a difference-in-differences analysis, we find that floor traders are important contributors to market...

We investigate how the introduction of market data fees impacts trading and market quality. We find that data fees decrease the fee-introducing exchange’s market volume, its time with competitive quotes, its visible liquidity, and its role in price discovery. We observe brokers routing market...

We investigate institutional trading of American Depositary Receipts (ADRs) around ex-dividend dates motivated by recent concerns of abusive practices of ADR pre-releases and illegal refunds of dividend withholding taxes. Using data on US stocks, foreign stocks, and ADRs from 1999 to 2014, we...

We examine empirically the role of high-frequency traders (HFTs) in price discovery and price efficiency. Based on our methodology, we find overall that HFTs facilitate price efficiency by trading in the direction of permanent price changes and in the opposite direction of transitory pricing...

We examine the role of high-frequency traders (HFTs) in price discovery and price efficiency. Overall HFTs facilitate price efficiency by trading in the direction of permanent price changes and in the opposite direction of transitory pricing errors, both on average and on the highest volatility...

We examine empirically the role of high-frequency traders (HFTs) in price discovery and price efficiency. Based on our methodology, we find overall that HFTs facilitate price efficiency by trading in the direction of permanent price changes and in the opposite direction of transitory pricing...

We examine the effects of high frequency traders (HFTs) on liquidity using the September 2008 short sale ban. To disentangle the separate impacts of short selling by HFTs and non-HFTs we use an instrumental variables approach exploiting differences in the ban's cross-sectional impact on HFTs and...