Société Générale's own wrongs were later established by a French jurisdiction, which led the Cour de cassation to cancel the €4.9 billion sanction on Kerviel.
Bank officials claim that Kerviel tried to conceal the activity by creating losing trades intentionally so as to offset his early gains.
The bank then closed out these positions over three days of trading beginning January 21, 2008, a period in which the market was experiencing a large drop in equity indices, and losses attributed are estimated at €4.9 billion.
The bank claimed Kerviel "had taken massive fraudulent directional positions in 2007 and 2008 far beyond his limited authority"[8] and that the trades involved European stock index futures.
[5] City experts have expressed skepticism of the bank's account, saying that a pattern of closing out trades within the three-day cycle alleged could not be accomplished given the immense sums involved.
[15] On the eve and afternoon of January 25, 2008, police raided the Paris headquarters of Société Générale and Kerviel's apartment in the western suburb of Neuilly-sur-Seine[16] to seize his computer files.
[13] The investigation later widened to encompass his personal cell phone records, and to explore possible links to other individuals working at rival banks and private investment firms who may be involved.
Police are interested whether others were involved in either the trades themselves, or received notice of the bank's impending sell-off before the details of the scandal were publicly disclosed.
On January 29, 2008, investigating judges Renaud van Ryumbecke and Francoise Desset had rejected prosecutor Jean-Claude Marin's bid to charge Kerviel with the more serious crime of "attempted fraud" and refuse bail.
[27] Caroline Guillaumin, a spokes-woman for Société Générale, stated that the restitution was "symbolic", and that the bank had no expectation that the sum would be paid.
[30] A Federal Reserve spokesperson denied the central bank knew of Société Générale's situation when it made its decision.
[10] Société Générale's investment banking chief, Jean Pierre Mustier, acknowledged that the three days of forced selling played a role in the market's overall decline, but characterized that impact as "minimal".