Jérôme Kerviel (born 1977) is a French trader who has a pending appeal of his conviction in the 2008 Société Générale trading loss for breach of trust, forgery and unauthorized use of the bank's computers, resulting in losses valued at €4.9 billion. Société Générale characterizes Kerviel as a rogue trader and claims Kerviel worked these trades alone and without its authorization. These assertions have been met with skepticism by some of Kerviel's former colleagues and acquaintances, as well as by some members of the news media. Kerviel had told investigators that his trading behavior was widespread at the company and that getting a profit makes the hierarchy turn a blind eye. Kerviel published a book in May 2010, L'engrenage: Mémoires d’un Trader (Downward spiral: Memoirs of a Trader), in which he alleges that his superiors knew of his trading activities, and that the practice was very common.