In response to a regulatory enforcement, the Island electronic communications network recently stopped displaying its limit order book in the three most active exchange-traded funds (ETFs). As a result of this reduction in pre-trade transparency, this dominant venue's share of trading activity...

We examine the impact on stock prices of a major upgrade to the New York Stock Exchange's trading environment. The upgrade was sequentially implemented across groups of stocks. The upgrade improved information dissemination on the trading floor and reduced the latency in reporting trades and...

This paper studies the ability of non-informational order imbalances (buy minus sell volume) to predict daily stock returns at the market level. Using a model with three types of participants (an informed trader, liquidity traders, and a finite number of arbitrageurs), we derive predictions...

Algorithmic trading has sharply increased over the past decade. Does it improve market quality, and should it be encouraged? We provide the first analysis of this question. The NYSE automated quote dissemination in 2003, and we use this change in market structure that increases algorithmic...

Short-sale bans have been utilized globally as a regulatory tool during periods of financial crisis. This paper reviews the observed intended and unintended effects of short-sale bans. Research has documented pervasive effects spanning many financial markets that include options, convertible...

This paper examines the trading process outside of normal trading hours. Although after-hours trading volume is small, after-hours trades are more informative than trades during the day, and are associated with significant price discovery. Spread-related trading costs are also more than twice as...