Jérôme Kerviel bank a profit of US$2 billion as of 2007. Managers for Société Générale have described some of the means Kerviel employed to avoid the bank's internal controls and escape detection. Its Executive Chairman Daniel Bouton describes the pattern as like "a mutating virus" in which hundreds of thousands of trades were hidden behind offsetting faked hedge trades. Officials say Kerviel was careful to close the trades in just two or three days, just before the trades' timed controls would trigger notice from the bank's internal control system, and Kerviel would then shift those older positions to newly initiated trades. City
Jérôme Kerviel over three days of trading beginning 2008, a period after which the market experienced a large drop in equity indices, and losses attributed are estimated at (). The bank claimed Kerviel "had taken massive fraudulent directional positions in 2007 and 2008 far beyond his limited authority" and that the trades involved European stock index futures. Though bank officials say Kerviel apparently worked alone, skeptics question how unauthorized trading of this magnitude could go unnoticed. Kerviel's unassuming background and position have heightened the skepticism that he worked alone. Some analysts suggest that unauthorised trading of this scale may have gone unnoticed