The past five years have seen the oil trading business swing from one extreme to another and then back again. Prior to December 2001 it was in strong growth mode, with many US banks in particular ramping up their operations. Then came Enron.

Almost overnight, oil and other energy markets went into massive retrenchment. Trading operations were shut down or radically scaled back, with the European regional operations of US banks being hit particularly hard.

There were some exceptions to this