Jerome Kerviel, sentenced in 2010 on charges of forgery, breach of trust and unauthorized computer use, claims that Societe Generale was aware of his activities and only cried foul when his trades lost money.
The bank, France's second largest, has said Kerviel acted on his own as he masked the fact that he had made bets worth nearly €50 billion — beyond the amount authorized for one trader. The bank says it cost €4.9 billion — around $7 billion at the time — to unwind those trades.
Kerviel was ordered to pay that same staggering sum back to the bank as part of his sentence — an order that drew gasps from the courtroom. He was also sentenced to three years in prison but was set free pending the appeal.
The 35-year-old former trader looked calm as he entered the courtroom Monday.
He plans to argue that the bank manipulated some of the evidence used to convict him, saying that a section of an audio recording on which he stated the bank was in the loop had been tampered with. In April, he filed a lawsuit against the bank for obtaining a verdict under false pretenses. He also disputes the amount that Societe Generale lost, saying it has recouped some of the €4.9 billion.
"We will explain that the bank knew and when they knew," Kerviel's lawyer, David Koubbi, said recently. "Mr. Kerviel has the sad distinction of the most harshly sentenced man in the world."
The bank has denied tampering with the recordings.