Arbitrage and liquidity are interrelated. Liquidity facilitates arbitrageurs’ trading on deviations from the law of one price. However, whether arbitrage opportunity leads to an increase or decrease in liquidity depends on the cause of the deviation. A demand shock leads to greater liquidity,...

We study three cases in which specialized arbitrageurs lost significant amounts of capital and, as a result, became liquidity demanders rather than providers. The effects on security markets were large and persistent: Prices dropped relative to fundamentals and the rebound took months. While...