Investment banks' fixed income businesses — long seen as the engine room of profits — are likely to see an almost 30% year-on-year decline in revenues in the fourth quarter, marking an ignominious end to a year in which annual industry-wide revenues for the business are likely to be down more than a fifth.

In a note published this morning by JP Morgan's banks team, led by Kian Abouhossein, the US investment bank forecast a 29% year-on-year fall in fixed income, currencies and commodities revenues across the global investment banks in the fourth quarter.