The man who 'broke' the Bank of England has made another billion betting against a currency.

The man who 'broke' the Bank of England has made another billion betting against a currency. Photo: Getty Images

George Soros has made almost $US1 billion($970 million) since November from bets that the yen would tumble, according to a person close to the billionaire's $US24 billion family office.

The Japanese wager helped the firm return about 10 per cent last year and 5 per cent so far this year, said the person, who asked not to be named because the firm is private. The yen has weakened 17 per cent versus the dollar since about the start of the fourth quarter, the worst performance over a similar period since 1985.

The yen slumped and Japanese stocks rallied last week as Prime Minister Shinzo Abe pressed the Bank of Japan to introduce additional stimulus measures. The bank's governor, Masaaki Shirakawa, and two deputies will step down next month, allowing Mr Abe to pick leaders to implement his plan for expanded monetary easing.

Scott Bessent, chief investment officer at New York-based Soros Fund Management LLC, also has 10 per cent of the firm's internally managed portfolio betting on rising shares in Japan, said the person. Japan's benchmark Nikkei 225 stock index has jumped about 28 per cent since the end of September.

Mr Bessent worked for Mr Soros in 1992 when Mr Soros and his chief strategist Stan Druckenmiller made a $US10 billion bet that the Bank of England would be forced to devalue the pound. That wager netted $US1 billion. At the time Mr Soros' Quantum fund was worth $US3.3 billion.

Mr Bessent left the firm in 2000, and returned to be CIO in 2011.

Michael Vachon, a spokesman for the firm, said he couldn't comment on the trades, which were earlier reported by the Wall Street Journal.

Bloomberg