With the U.S.–Japan Rate Gap Still Wide, Why Has the Yen Suddenly Strengthened? Recent USD/JPY Moves and Foreign Exchange Intervention

1. USD/JPY Falls Again as the Yen Rebounds

Since the start of 2026, the yen has continued to be influenced by the U.S.–Japan interest rate differential, monetary policy expectations and international capital flows. Although the Bank of Japan has gradually raised its policy rate, the dollar still offers a substantial interest rate advantage over the yen, leaving the Japanese currency under depreciation pressure. Recently, however, conditions in the foreign exchange market have shifted. Based on cross rates calculated from the European Central Bank’s (ECB) daily foreign exchange reference rates, USD/JPY stood at approximately 158.24 on October 19 and had fallen to around 156.80 by October 23, a cumulative decline of approximately 0.91%, indicating that the yen had strengthened against the dollar. On October 22, in particular, global financial markets were affected by selling pressure in technology stocks, concerns over AI investment and geopolitical uncertainty. Demand for safe-haven assets increased, and the yen and Swiss franc were among the stronger-performing major currencies that day. This shows that, in addition to interest rate differentials, changes in market risk appetite can also generate significant short-term exchange rate movements.

2. The U.S.–Japan Rate Gap Remains Wide: Why Does the Dollar Still Appeal?

Interest rate differentials have long been an important factor influencing USD/JPY. On September 16, 2026, the U.S. Federal Reserve announced a 25-basis-point rate increase, raising the target range for the federal funds rate to 3.75%–4.00%. The Bank of Japan, meanwhile, adjusted its policy rate target to 1.25% in September. A simple comparison of policy rates therefore leaves the U.S. rate range approximately 2.50–2.75 percentage points above Japan’s. U.S. 10-year government bond yields are also approximately 204.6 basis points higher than Japan’s. Higher yields on dollar-denominated assets generally make the dollar more attractive to some international investors. When investors choose to hold dollar-denominated deposits or bonds, this can increase demand for dollars and put pressure on the yen. However, interest rate differentials are not the sole determinant of exchange rates. If markets expect the Bank of Japan to continue raising rates, or see a possible shift in the Federal Reserve’s monetary policy direction, investors may adjust their foreign exchange positions in advance. In addition, when global market volatility intensifies, some investors may unwind carry trades funded in yen, potentially driving a short-term appreciation of the currency. Thus, even while the U.S.–Japan interest rate gap persists, USD/JPY will not necessarily continue to rise.

Note: Policy rates reflect the latest decisions made before October 24, 2026. Government bond yields for both countries are as of October 22, 2026, with a yield differential of 2.046 percentage points. Interest rate indicators and yield calculation methodologies differ across countries.

3. Coordinated U.S.–Japan Intervention: Why Did the Authorities Act to Support the Yen?

Alongside interest rate policy, foreign exchange markets continue to monitor intervention by the Japanese authorities. In July 2026, the yen came under substantial depreciation pressure, prompting Japan and the United States to take more direct action. According to data released by Japan’s Ministry of Finance, Japan’s foreign exchange intervention operations totaled ¥15.3993 trillion during the period from July 30 to August 26. The Ministry of Finance also issued an official statement on August 3, confirming that it had coordinated yen purchases with the U.S. Treasury on July 31, U.S. Eastern Time. Officials said the action was intended to address recent excessive yen volatility and disorderly market conditions. This was also the first coordinated foreign exchange intervention in 15 years since the 2011 Great East Japan Earthquake.

Yen-buying intervention typically involves the authorities selling foreign currency and buying yen in the foreign exchange market, increasing demand for the yen to curb rapid depreciation. Because official intervention can involve substantial sums, and market participants may adjust their foreign exchange positions at the same time, it can often intensify short-term exchange rate volatility. For example, during intervention-related trading in late July 2026, USD/JPY fell approximately 2.4% in a single day. Looking further back to Japan’s intervention on April 29, 2024, USD/JPY dropped rapidly from an intraday level of around 160.25 to 154.40, a high-to-low intraday range of approximately 3.6%. These episodes illustrate that official intervention can have a marked short-term impact on exchange rates, although whether that impact lasts still depends on market expectations and economic fundamentals.

4. Can Official Intervention Change the Yen’s Long-Term Trend?

Foreign exchange intervention can influence short-term market supply and demand, as well as investor expectations, through direct currency purchases and sales. Whether it can durably change the direction of an exchange rate, however, depends on broader economic and financial conditions. First, the U.S.–Japan interest rate differential remains substantial. Even if Japan gradually raises rates, international capital may remain attracted to dollar-denominated assets as long as they offer relatively higher yields. Second, expectations for future monetary policy may matter more than current interest rate levels. If investors believe that U.S. rates will remain higher for longer, the dollar may continue to receive support. Conversely, if the Bank of Japan signals a more aggressive approach to rate increases, demand for the yen could rise. Japan also depends heavily on imported energy. Higher international oil prices could increase import costs for businesses and households, in turn affecting the trade balance and foreign exchange supply and demand. Exchange rate movements typically reflect the interaction of multiple factors, however, so a change in any single economic indicator cannot be interpreted as an inevitable cause of yen appreciation or depreciation. Therefore, although both the coordinated U.S.–Japan intervention in July and the yen’s rebound in October were associated with yen appreciation, the underlying market mechanisms were not entirely the same.

5. Upcoming U.S. and Japanese Central Bank Meetings: What Will Markets Watch?

Financial markets will next face important monetary policy meetings in both the United States and Japan. Following the Federal Reserve’s September rate increase, markets will continue to assess whether inflation and employment data justify further tightening. For USD/JPY, the Fed’s policy direction affects not only dollar interest rates but also expectations for the future U.S.–Japan rate differential. In Japan, beyond whether the Bank of Japan adjusts rates further, its assessment of prices, wages and economic growth may influence market views on the yen. International investors should also monitor changes in U.S. and Japanese government bond yields, risk sentiment in global financial markets and any new foreign exchange intervention information released by Japan’s Ministry of Finance. Overall, although the yen has recently rebounded, the U.S.–Japan interest rate gap remains. Whether the yen can sustain its appreciation trend will depend on the combined evolution of monetary policy in both countries, capital flows and conditions in international markets.