Using a novel dataset where all traders are identifiable, we examine trading in the shares of a major company on the London Stock Exchange before 1920. Our main finding is that bid-ask spreads increased in the presence of informed trades. However, we also find that spreads narrowed during...

This paper analyzes brief episodes of high-intensity quotes turnover and revision-"bursts" in quotes-in the U.S. equity market. Such events occur very frequently, several hundred times a day for actively traded stocks. We find significant price impact associated with these market makers...