A UBS rogue City trader who believed he had "the magic touch" gambled away £1.4bn of the bank's money in a bid to improve his status, bonus and job prospects, a court heard.
Kweku Adoboli, 32, is on trial at Southwark Crown Court accused of two counts of fraud and two counts of false accounting. He pleaded not guilty to all charges.
The investment banker is accused of allegedly breaking banking rules against-high risk trading then inventing false clients and lying to his employer in order to cover up his illegal actions, prosecution said.
Sasha Wass QC said: "He is on trial because he lost his bank $2.3billion (£1.4bn). He fraudulently gambled it away.
"He also wiped around 10 per cent or about $4.5billion (£2.8bn) off his bank's share price.
"He did all of this by exceeding his trading limits, by inventing fictitious deals to conceal this and then he lied to his bosses.
"Mr Adoboli's motive for this behaviour was to increase his bonus, his status within the bank, his job prospects and of course his ego.
"Like most gamblers, he believed he had the magic touch. Like most gamblers, when he lost, he caused chaos and disaster to himself and all of those around him."
Wass added Adoboli, who earned £360,000 in salary and bonuses in 2010, "faked bookings, he created false accounts and conducted himself as a master fraudster, deliberately and systematically deceiving and defrauding the bank which employed him."
At one stage Adoboli's gambling could have lost the bank £7.4bn in unhedged investments.
Wass said: "He had been sucked into the gambler's mindset and he started throwing good money after bad.
"He was risking the very existence of the bank by gambling its resources, ultimately for his own benefit."
Adoboli from Clark Street, Whitechapel, east London, is accused of losing the money in Britain's biggest alleged banking fraud.
Ghana-born Adoboli was arrested in September 2011 after UBS discovered what it called "unauthorised trading" at its investment banking arm.
The episode knocked back UBS in its efforts to recover from near collapse during the 2008 financial crisis.
The trial is scheduled to last eight weeks.