Selling the yen has been the hottest currency trade for several months now. But ever since the Bank of Japan announced stimulus plans that fell short of investor expectations, the yen has been bouncing back.
Is the freefall over?
Not likely, says Kathy Lien, a managing director at BK Asset Management and a CNBC contributor. "I think it's basically profit taking after such an extended move," she told CNBC's Melissa Lee.
In Lien's view, investors set the bar so high for Bank of Japan action that the risk of disappointment was high. "The BOJ needed to deliver everything on point in order for dollar-yean to continue to rally," she says. What they did come up with - an inflation target of 2%, up from 1%, and stimulus starting in 2014 - "just wasn't enough for the market."
(Read more: Quantitative Easing: CNBC Explains)
At the same time, U.S. interest rates have been under pressure, which is helping to send the dollar lower.