As a serious golfer such as Stan O’Neal knows only too well, one bad hole can ruin an otherwise great round. This week, Merrill Lynch’s chief executive had the equivalent of a triple bogey: $8bn of writedowns in the investment bank’s mortgage securities business – a Wall Street record – leading to losses of $3.5bn in the third quarter.

Some of Mr O’Neal’s board directors have argued that he should be allowed one mistake – even this big – given the turnround Merrill has achieved under his leadership. But at least one director is pressing for his removal and has discussed possible successors from outside the company.