During the Flash Crash on May 6, 2010, a short period of high stock market volatility, some stock prices declined to $0.01, while others increased to $100,000. Examining Intermarket Sweep Orders (ISO) before, on, and after May 6, we find that ISO use is substantially higher on May 6. For those...

In a single market, liquidity supply has two dimensions--price measured by the quoted spread, and quantity measured by the quoted depth. A third liquidity dimension, market breath, should be added when multiple markets quote the same security and there are enforceable regulatory penalties for a...