It has been five years since the so-called flash crash on Wall Street raised big questions about computerized trading. What caused the flash crash has been a topic of debate ever since. U.S. officials revived the debate this week by arresting a little-known trader in London.
May 6, 2010 started out as an ordinary trading day on Wall Street. Then, at around 2:45 in the afternoon, the Dow Jones Industrial Average plunged nearly 600 points within the space of a few minutes, before correcting itself.