According to a banker with a close knowledge of Mr Adoboli's alleged activities, one reason why UBS failed to identify the unauthorised deals till Wednesday was that Mr Adoboli had a close knowledge of UBS's back office or administration procedures: he previously worked in the back office before becoming a trader.
Less than two years after Enron was formed, a trader in the company's Valhalla office lost hundreds of millions of dollars betting the wrong way on crude oil.