It's the classic prisoner's dilemma: you're under investigation for manipulating Euribor rates. Do you shut up and let the regulator unearth what it may of your wrongdoings? Or do you admit culpability and give the regulator reams of information on the activities of your co-conspirators in return for being let off the hook?
If you're UBS, or Barclays, it's the latter.
The European Commission has fined eight banks €1.7bn for participating in cartels to manipulate the Euribor rate. However, both UBS and Barclays have been fined nothing at all after 'revealing the existence and extent of the cartels' that they and other banks were participating in.
In the case of UBS, this looks like an extremely cunning move. The European Commission's ruling makes UBS look like by far the worst perpetrator of the Euribor scam: it was involved in five infringements lasting a total of 25 months and had it not blown the whistle on everyone else, it would have been fined €2.5bn for its participation in the cartel. This would clearly have been extremely bad news for the UBS bonus pool.
Barclays also looks cunning: it was involved in a separate cartel for 32 months and would have been fined €690m had it not grassed on everyone else involved in the same cartel.
Meanwhile, poor naive and unscrupulous RBS looks like it's being disproportionately punished for its involvement in Euribor fixing compared to the big players who blew the whistle. The EU says the British bank participated in both cartels, once for 8 months and again for 16 months. During its involvement in the 'Yird cartel,' RBS had three infringements and was fined €259m. Citi had a similar number of infringements but was fined a mere €70m after its fine was reduced for cooperating with the investigation.
In total, RBS's unscrupulous traders have been fined €390m (£324m) today. This year's RBS bonus pool is said to be £500m and could be all but wiped out. RBS's naive and foolish traders will wish they'd been a bit quicker to blow the whistle on their co-conspirators whose bonus pools will remain helpfully intact.