When you are running a business you are responsible for what happens in your business. If your staff makes a mistake you have to fix it. If some of your staff a caught with their hands in the proverbial cookie jar – you are responsible in as much as you should have done your job and noticed something was wrong.
Have you been fooled? Are you incompetent? Or are you just bad at your job?
Who cares? Surely, as the CEO of one of the worlds foremost banking institutions, you should resign for your short-comings and failings?