Japan Interest Rates: Why the Yield Gap Still Drives USD/JPY

The interest rates remain at the heart of the market story in Japan. The large difference between the U.S and Japanese yields is continuing to put pressure on the yen and keep USD/JPY near high levels. This is why the Bank of Japan is in such a precarious situation. If it proceeds too slowly, the yen might fall further and raise the cost of imports. In case it goes too fast, it may damage an economy that remains fragile.

The U.S.-Japan Rate Gap Remains the Main Driver

The core reason for yen weakness is still the gap between Japanese and U.S. interest rates. The BOJ kept its policy rate at 0.75% in March, as shown in the chart below. Meanwhile, the target range of the Federal Reserve is 3.5% to 3.75%. That leaves a very wide policy-rate spread in place. That spread continues to lure investors to borrow cheaply in the yen and shift capital into dollar assets with higher yields, despite recent market moves.

This is why the remarks of Kanda are important. He does not mean that the yen is weak merely due to the short-term risk sentiment. He means that the greater problem is structural. As long as the market is convinced that the Fed can remain relatively stable and the BOJ is careful, the dollar remains at an edge over the yen. The USD/JPY will not decline significantly even in cases where the geopolitical pressures are alleviated and a portion of the safe-haven dollar purchases are abandoned since the yield difference remains in favor of the dollar.

That is also why the debate at hand is so sensitive. The headline CPI in Japan stood at 1.3% year-on-year in February 2026, down compared to recent highs. But the BOJ has still indicated it will keep increasing the policy rate in case the outlook of activity and prices changes as anticipated.

The central bank does not desire to respond to a single monthly inflation rate. It is observing the wider combination of wages, the cost of imports, energy and inflation expectations. If the BOJ moves too slowly, the yen would weaken and that would make imports more expensive.

USD/JPY Still Follows Yields More Than Headlines

The US dollar hit a seven-week low when Iran declared the Strait of Hormuz open, which contributed to the risk sentiment and decreased the demand for the dollar as a safe trade. The U.S. stocks also shot up. But the yen has risen slightly, and USD/JPY remained around 158.6.

At this moment, the interest-rate scenario remains biased towards a high USD/JPY. The 10-year yield of the U.S. Treasury stood at approximately 4.25% on April 17 whereas the Japanese 10-year yield was at 2.42%.

That is a smaller gap than the policy rate gap, though it is still big enough to stimulate dollar demand. The yen will not be able to mount robust recovery as long as U.S. yields remain well above Japanese yields unless market begins to reflect a higher level of BOJ tightening. Moreover, the trend for Japanese yields shows a clear upward momentum since 2023.

This is why the warning issued by Kanda on the background of the curve is so crucial. A central bank that appears to be slow when inflation threats are apparent will likely depreciate its currency. In Japan weaker yen at the time fed into imported inflation in the form of energy and food. That only underscores the importance of the next steps that the BOJ will take towards both the currency and bond markets.

From a technical perspective, USD/JPY remains in an upward trend. The pair is consolidating at the resistance of 160. A break above this resistance will fuel another surge.

Why the BOJ Is Trapped Between Inflation and Growth

The BOJ is currently facing the problem of making a very difficult decision. On one hand, they don’t want to harm a weakened economy. On the other hand, they can no longer ignore the cost of a continuously weakening yen. As a result of persistently weak yen and rising wages for nearly 4 years Japan’s inflation has remained within the target set by the BOJ due to higher imported prices. Therefore BOJ will need to contend with inflationary pressures which are not solely transitory.

According to the IMF, the BOJ can “look through” much of the inflation shock related to the Iran war because of limited secondary-round effects. IMF anticipates that the BOJ will continue to raise interest rates incrementally up to 1.50% by the end of 2027. That would further support the argument for “patience”. However, when markets start interpreting delays as lack of resolve, there can be significant costs associated with patience.

Thus, the next decision in Japan may be influenced more by credibility than by a specific data point. As long as the inflation risk is contained and the yen is kept stable, then the BOJ can do things at their own steady pace. But when USD/JPY starts to gain upward momentum above 160, then the pressure will mount on the BOJ to act quickly. Under those circumstances, the market may force the BOJ into acting before it is ready.

The Bigger Picture

Interest rates still drive Japan’s market direction. The large spread between the U.S. and Japanese yields is still in favor of the dollar and it puts pressure on the yen. This is why the BOJ cannot risk appearing to be too slow, particularly if a weaker currency increases the cost of imports and maintains inflation risks alive. Meanwhile, it cannot tighten too quickly as this could harm growth. This puts the BOJ on a narrow path where credibility is more important than the data. Once markets begin to think that the BOJ is behind the curve, USD/JPY and bond yields might start to soar and force stronger policy response.