Investment banks weren’t the most profitable of businesses last year. But things have just got a whole lot worse.

While many bankers have been focusing on the depressing headline news triggered by a collapse in confidence in the financial markets - underlying revenues across the industry were down 17% last year and pre-tax profits collapsed by 54% according to my analysis of the big investment banks that have reported their results so far * - there is an elephant in the room that will make matters even worse.