Citigroup may have been a poor investment over the past five years. But the US bank has learnt one valuable thing from the financial crisis. This is that the boss of a large and complex financial institution should be answerable to its board and not vice versa.

It has not been revealed whether Citi’s directors, led by new chairman, Mike O’Neill, demanded the replacement of Vikram Pandit this week. Since the chief executive’s abrupt departure, both sides have confined themselves to diplomatic generalities. The board had ample reason to let him go, however.

Even taking into account the titanic mess Mr Pandit inherited when he assumed the top job in 2007, his achievements have been meagre. True, he dismantled some of the financial timebombs ticking within the balance sheet. But he also presided over a 90 per cent fall in Citi’s share price – worse than any other US financial company bar AIG. Meanwhile, his relations with regulators and investors have been fraught. The authorities shot down the bank’s $8bn share buyback earlier this year. Mr Pandit’s own $15m pay packet for last year was rejected by shareholders.