The yen's fall against the dollar the past few weeks has been remarkably fast, and calculated from where it is now around 97.70 yen, the dollar has jumped nearly 9 percent this month, on track for its biggest such gain since August 1995.
The yen surged last year as the worsening financial crisis forced investors to unwind risky carry trades - meaning they had to buy lots of yen - under the belief that Japan's economy and banks were holding up through the storm.
Only last month, the yen hit an over-13-year high of 87.10 per dollar. So why has the Japanese currency fallen so fast?
Analysts tell me one reason is some traders and investors who thought it would continue to rise, perhaps as far as 80 or even 70 yen, got out of such bets.
One catalyst was data showing the sharpest economic contraction in 35 years in the last quarter.