Yen Volatility Intensifies Amid Fed And BOJ Policy Watch

If you plan to travel to Japan this year, hold yen-denominated assets, or intend to borrow and buy property there, this week's sharp currency swings are the signal to watch. On September 4 in New York, a strong U.S. employment read first pushed traders to sell yen and buy dollars, then the mood flipped and buyers piled back into the yen. Two violent reversals in a single day point to one question: the Federal Reserve and the Bank of Japan are moving rates in opposite directions, and the market has not settled who moves first, or by how much.

There is a parallel signal. The same week, Japan's 10-year government bond yield topped 3% for the first time in about 30 years (see our separate analysis). Rising long-term yields mean the market is already pricing the BOJ's exit from easing, while the U.S. side waits for the Fed to pivot toward cuts. As that gap narrows, the carry structure that kept the yen weak loosens, and the yen can snap higher. Japanese authorities add another variable: when the yen has fallen sharply and one-sidedly in the past, the Finance Ministry has intervened by buying yen, so bigger swings automatically raise the market's guard.

For Taiwanese readers this sets the pace on three fronts: convert travel money in tranches rather than all at once; treat the exchange rate as part of your return on Japanese assets; and if you borrow to buy property, track both rising rates and a firming yen. Watch the next U.S. jobs and inflation prints, the BOJ's language on hikes, and how bluntly Finance Ministry officials talk about the currency.