Many anonymous traders are implicated in the tall stack of documents regulators published this week detailing Royal Bank of Scotland's attempts to rig the lending benchmark known as Libor. But only one trader is cited by name: a 33-year-old so brainy yet socially awkward that colleagues nicknamed him "Rain Man".

Regulators portray that man, Tom Hayes, as the connective tissue in pervasive efforts by several banks to boost trading profits by manipulating the London interbank offered rate. Hayes hopscotched from RBS to the Royal Bank of Canada to UBS to Citigroup, picking up the contacts and know-how that would be necessary to game Libor.