Automation and trading speed are increasingly important aspects of competition among financial markets. Yet we know little about how changing a market's automation and speed affects the cost of immediacy and price discovery, two key dimensions of market quality. At the end of 2006 the New York...

This paper combines daily non-public data on buy and sell volume by institutions from 2003 through 2005 for NYSE-listed stocks with all news announcements from Reuters. Natural language processing categorizes the sentiment associated with each news story. We use institutional order flow (buy...