The Wall Street Journal got it straight from the horse's mouth.
The answer, said Guerrera, was 'disarmingly simple'.
Ermotti said: 'We don't have the goodwill from our shareholders to continue throwing money away into something that doesn't cover its cost of capital'. Simples.
In the meantime, Reuters reports that Nomura plans to complete the merger of its European equities units by June, in a move that will position the Japanese to meet British regulatory reforms outlined last week.
And the news agency also reports that Jersey's financial watchdog is to probe anti-money laundering systems and controls at HSBC, following a report that Europe's biggest bank was harbouring money for convicted criminals.
Finally, Bloomberg reports that Jerry Yoon, who was head of equity derivatives flow in Asia for Royal Bank of Scotland, and Nick Langford, who ran convertible bond sales in the region, said they have left the bank.
The departures come as RBS seeks to combine its investor products and equity derivatives businesses into its global trading arm, according to a September 28th internal announcement seen by Bloomberg.
UBS Tells Why it Cut Off a Limb (subscription content)