This 4.7 billion dollar loss is completely unacceptable. The CEO should be fired, and the board replaced.
US law should be changed so that senior executives and board members are personally financially liable without any insurance to shareholders for losses like this. Otherwise, you will have what Credit Suisse did here happen over and over again – The executives will collect massive multi-million dollar bonuses for years until the risk catches up with them and a big loss happens and they get fired but walk away with no real punishment.