A nine-month return to profitability for UBS's investment bank came to an abrupt end this morning after the division reported a loss for the third quarter, thanks in part to one of the most difficult three months of trading in the bank's recent history. Equities trading gave its second-worst performance in seven years, while in fixed income it was down by almost a half from a previous result that had been seen as a change in fortunes.

After three consecutive quarters of profitability, the investment bank reported a pre-tax loss of Sfr 406m ($417m), reflecting significant shortfalls across investment banking and sales and trading. Of the seven major investment banks to have published earnings so far, only Morgan Stanley and UBS have now reported losses.