STEPHANE DE SAKUTIN/AFP/Getty Images
Year made public: 2008
Estimated Losses: $8 billion
Société Générale trader Kerviel is said to have made tens of millions worth of futures trades without the knowledge of his superiors. Once the French bank discovered his actions, it realized that his trades had already generated tremendous losses. Kerviel is awaiting trial and if convicted, faces up to three years in prison.