Japan's yen jumps against the dollar after earlier plunge

The Japanese yen jumped suddenly against the dollar on Monday, with traders on high alert for signs of intervention by Japanese authorities to boost the currency that is languishing near 34-year lows.

The dollar fell sharply to 156.55 yen from as high as 160.245, and it was not immediately clear what was behind the move.

Traders are on edge for any signs of action from Tokyo to prop up a currency that has fallen 11% against the dollar so far this year.