Mother Jones: News of the Federal Reserve not tapering its bond buying program takes seven milliseconds to get to Chicago. However, several huge orders based on that decision were placed on Chicago exchanges two to three milliseconds after 2 p.m.
Reporters get the Fed release early, but they get it in a secure room and aren't permitted to communicate with the outside world until precisely 2 p.m. Still, maybe someone figured out a way to game the embargo. It would certainly be worth a ton of money. Investigations are ongoing.