A trade (buy or sell order) that flashes information from an exchange about incoming orders a fraction of a second (milliseconds) before the flash information is communicated to the trading system. The trade will be revealed only to fee-paying market participants, for a fraction of a second , so that they can decide whether or not to provide a cross.

Flash trades have been terminated by many exchanges, mainly due to the fact that the structure creates a two-tier market that can favor certain investors and disfavor others, leading to a compromised market fairness.