The Japanese currency has dipped below the 100 yen mark against the US dollar for the first time since April 2009. It broke the threshold in New York yesterday and was trading close to 100.8 yen to a US dollar in Asia today. The yen has dipped nearly 25 per cent against the US dollar since November, after Japan unveiled a series of aggressive moves to spur growth in its economy. The Japanese currency has come close to the 100 yen to a US dollar mark in recent days, but has been unable to breach that level.