Speculation is that options exchanges would seek to bust Thursday's trades, possibly after the next day's opening. This is one of the worst actions possible. Everybody can see how the new day is trading. I thought CBOE rulebook, at least, stated trades can be busted, but in no circumstances can it be done after the next day's open. http://online.wsj.com/article/BT-CO-20100507-711302.html?mod=WSJ_latestheadlines