Does flash trading cheat the average investor?

The Securities and Exchange Commission (SEC) is considering a rule to ban flash trading, in which computers fed with order information trade stocks moments before the exchange executes those orders. Conceptually, it sounds like an open and shut case of insider trading to me.

The SEC's thoughts on flash trading are pushing some to ban the practice preemptively. Two exchanges -- NASDAQ and Bats Global Markets -- where flash trading used to occur have ended the practice. But flash trading still takes place at Direct Edge Holdings LLC.