We develop a return variance decomposition model to separate the role of different types of information and noise in stock price movements. We disentangle four components: market-wide information, private firm-specific information revealed through trading, firm-specific information revealed...

We analyze trading dynamics as successive high-frequency trading (HFT) firms begin to trade stocks in an equity market. Entrants compete with incumbents for volume, and there is crowding out. Earlier entry is associated with larger effects. After Passive HFT entry, incumbent spreads tighten....

We provide evidence on market structure and the cost of raising capital by examining market structure changes in US equity markets. Only the Nasdaq's Order Handling Rules (OHR), the one reform that reduced institutional trading costs, lowered the cost of raising capital. Using a...