Abstract
In order to better understand this study, I think that we have first to explain what happened in the French Bank crisis, and who its actors were. This major crisis was made public on 24th January 2008. On this date, the CEO of the French bank, Daniel Bouton, announced a loss of about 7.1 billion, mainly due to one person. If we trust the official announcement, the trader Jérome Kerviel (about 5 billion due to him and about 2.1 due to the subprime crisis) was responsible for it. The investigation about this case is still not complete, but if we assume that the figures given by the CEO are true, it is the most significant loss caused by a trader in the history of the French bank. But how could only one trader generate an important loss for a group like Société Générale? When the bank discovered these operations of the trader (the 19th January 2008), around 50 billion were submitted to the variation of the market, resulting, in financial terms in an open situation.
