IB: To HKMEX,NYMEX,NYSELIFFE traders: Thu Aug 25 13:54:57 2011 EST As a result of the continued volatile trading environment, please be advised that exchange margins and/or house margins are likely to increase overnight and over the next couple of days, particularly in the metals. For exchange specific increases, please visit the respective websites. IB will also be increasing the gold derivatives margin. Please monitor any affected holdings closely and manage your risk accordingly.