UBS's rogue trader: Martingale gambler

He allegedly adopted an approach known in the gambling world as "martingale system": a gambler doubles his bet after each loss and continues to do so until he eventually wins--or runs out of money. Starting in 2008 Mr Adoboli hid his actions and losses through the creation of false accounts and clients, according to Ms Wass, who described Mr Adoboli as "a plausible liar and an accomplished fraudster".

"This wasn't a one-off period of madness, not a mere rogue trader carried away on a period of euphoria, but a protracted and sophisticated manipulation to puff up his earnings," she told the court.