A year ago, some analysts at Deutsche Bank made a striking call: at a big financial industry conference in Barcelona, they predicted that the subprime sector was heading for problems – even though most large banks were relatively upbeat about the sector at the time.

A year later, senior Deutsche Bank officials are keen to avoid seeming too smug about the call. But the German bank recently admitted its first-quarter profits had been significantly boosted by its bets in the subprime world, after the sector – which lends to borrowers with poor credit histories – started to turn sour earlier this year.