The Japanese yen is on a bumpy path toward strengthening after Friday*s central bank policy change, threatening to upend the carry trade, one of this year*s most popular strategies, as the currency inevitably becomes more expensive.

The BOJ kept its short-term interest rate target below zero, but shook markets by adjusting a policy that had effectively capped the 10-year government bond yield at 0.5%.

The wild swings in the yen, which saw its most volatile trading day for months, reflect the initial confusion among traders and investors about what this might mean.