A famous example is the (in)famous trader Jérôme Kerviel who was deemed responsible for a 4.9 billions euro loss at Société Générale. Having worked in Middle O

A famous example is the (in)famous trader Jérôme Kerviel who was deemed responsible for a 4.9 billions euro loss at Société Générale. Having worked in Middle Office before being promoted to the Front, he had a really good knowledge of how operations and risk management worked in the bank (plus some still working write accesses to specific systems) which allowed him to mask his very large positions with fake opposite trades that he was putting in every day before the nightly risk snapshot and cancelling before they could be confirmed. The guy basically did not take any holidays in two years - otherwise his large positions would have appeared on Risk radar pretty quickly... If you are into those stories and want much more details than my poor summary I really recommend reading the SocGen post-mortem investigation. Disclaimer: I worked at Société Générale during the Kerviel era - also there is a lot of controversy in France about how much the bank knew and let things happen (Kerviel was making a lot of profits - until he wasn’t) and if that was used to cover subprime related loss - this post does not represent an opinion on this case!