Nitpick: When exchanges have busted trades there is a "at or below $XX.XX" condition as well as the "between XX:XX and YY:YY" condition. In the Flash Crash as

Nitpick: When exchanges have busted trades there is a "at or below $XX.XX" condition as well as the "between XX:XX and YY:YY" condition. In the Flash Crash as well as the Knight Capital incident "up/down 30% from the Previous Close" was the price collar (anything outside that was busted and anything inside stood). Of course there is no guarantee that the same criteria will be used the next time around so caveat emptor.