Many began outlining layoffs plans 18 months ago and are now cutting more deeply as they reassess their entire business to cope with tougher capital rules, while some are cutting because of acquisitions or mergers they are involved in.

Switzerland's UBS in October added 10,000 job cuts to the 3,500 it had earmarked last year, after deciding to exit most of the rates and debt trading.

Staff cuts announced since mid-2011 or reported to be in the works at major banks have now reached 158,000.

Below are aggregates of various redundancy rounds. They are likely to be conservative figures, as not all banks have announced lay-offs publicly, and the number does not take into account smaller investment banks, boutiques and brokers. The data also shows the net job losses (or job additions) at these firms since the end of 2009, when the euro zone debt crisis began.

Job cuts announced since 2011: 157,969

Jobs lost at these firms since end 2009: 167,216

Jobs created since 2009: 83,553

Net jobs lost since end 2009: 83,663