Description:Just days after vowing to stay in his post Swiss central bank chief Phillipp Hildebrand has quit. He'd been facing growing criticism after a controversial currency trade made by his wife in August. Hildebrand's wife Kashya, a former trader who now runs a Zurich art gallery, bought 400,000 Swiss Francs worth of dollars from Sarasin Bank three weeks before her husband oversaw steps to cap the rise of the franc.(2:07)