The French Fraud King - $7.14 billion fraud by one man

He used to be in middle office and still had passwords. He took large one way trades, and booked fake trades to reverse them (typical method for a delta one desk, but he was not booking the reverse). His VaR would simply be the net of the fake and real trade - he kept rolling the fake trades so not to communicate the trade to them (they would not know of it) - a lot of work.

The way he was caught is that the fake reverse trade on one deal took the counterparty over its credit limit, so would have been subject to margin calls. I find it crazy that he was allegedly trying to hide the 1.5bn profit from 2007 when he managed to wipe it out, and turn it into the 5bn loss.