George Soros made almost $1 billion since November from bets that the yen would tumble, according to a person close to the billionaire's $24 billion family office.
The Japanese wager helped the firm return about 10 percent last year and 5 percent so far this year, said the person, who asked not to be named because the firm is private. The yen has weakened 17 percent 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 as Prime Minister Shinzo Abe pressed the Bank of Japan to introduce additional stimulus measures. BOJ Governor Masaaki Shirakawa and two deputies will step down next month, allowing Abe to pick leaders to implement his plan for expanded monetary easing.