Dollar Nears Seven‑Week High as Yen Slides Despite BoJ Rate Hike

In the week ending September 19, the U.S. dollar strengthened sharply, with the dollar index rising by approximately 1.2%, pushing it close to a seven‑week high. At the same time, USD/JPY surged following a Bank of Japan rate hike that lacked hawkish forward guidance, causing the yen to weaken significantly.

The dollar index, which tracks the U.S. dollar against a basket of major currencies, gained around 1.2% during the week, drawing near to its strongest levels in seven weeks. This rise underscored renewed dollar strength across global markets. Global foreign exchange markets and interest rate trades were dominated by this upward momentum.

The Bank of Japan delivered a 25‑basis‑point rate increase, raising its policy rate to 1.25%—a 31‑year high. However, the decision featured a split vote and lacked any forward‑looking hawkish communication, prompting USD/JPY to climb despite the rate move. With the BoJ failing to signal further tightening, the yen weakened materially over the week.

In addition to central bank developments, rising U.S. Treasury yields contributed to dollar strength. Two‑year U.S. Treasury yields reached their highest level since 2024, reinforcing the appeal of dollar‑denominated assets, even as energy prices fell. Precious metals, meanwhile, bucked the trend and managed to gain ground.

Collectively, these factors—dollar index gains, yen weakness post‑BoJ decision, and surging U.S. yields—signal a stronger greenback and lingering vulnerabilities for the yen.

Why It Matters

For FX traders and market watchers, this week’s developments are notable. A near seven‑week high in the dollar index points to renewed dollar strength across G10 currencies, while USD/JPY’s jump underscores market sensitivity to central bank messaging beyond policy moves. The yen’s weakness, despite a rate hike, may reflect broader concern over limited commitment from the BoJ to sustained tightening. Meanwhile, rising U.S. yields reinforce yield‑differential dynamics supporting the dollar.

Going forward, markets will closely monitor follow‑up communications from the BoJ, U.S. rate‑move expectations, and U.S. yield trends to gauge whether this dollar rally endures or the yen finds footing.