A year ago, Société Générale, lauded for its world leadership in equity derivatives finance, risked seeing its reputation in shreds, a sharp fall in business and class-action lawsuits from US investors enraged at the allegedly unauthorised trades of Jérôme Kerviel.

France’s second-biggest bank was in disarray after discovering Mr Kerviel’s €50bn ($65bn) exposure on a January weekend, which cost it €4.9bn to unwind, forcing it into a €5.5bn rights issue. It also revealed a €2bn subprime writedown, later revised to €2.6bn.