To US television networks, Jérôme Kerviel was the "$7bn man". To France's top banker, he was a "genius of fraud". What no one seemed sure of yesterday was precisely what led the 31-year-old trader to commit what Société Générale described as a "gigantic" act of deception.
"What is completely unbelievable is that this person didn't do it for his personal benefit. He didn't get anything from it," said a senior insider.
