The hill just keeps getting steeper for Morgan Stanley in fixed income. Not content with tripping up in fixed-income trading in three of the past four quarters and struggling to convince investors that it has a sustainable future as a mid-sized player in a market increasingly dominated by scale, Morgan Stanley has decided to change the senior management of its fixed-income business for the seventh time (on my count) in eight years.

The departure of Ken deRegt after two years of pushing water uphill means that the new co-heads of fixed income (Michael Heaney in New York and Rob Rooney in London) will inherit one of the toughest conundrums on Wall Street.