In an unprecedented step that has sent ripples through global financial markets, Japan and the United States have confirmed a rare coordinated currency intervention aimed at reversing the Japanese yen’s steep slide to a four-decade low and stabilizing the beleaguered Japanese currency. Japanese officials have signaled they are fully prepared to take additional coordinated action if market volatility returns, underscoring the seriousness of their commitment to curbing excessive yen weakness.
The joint intervention was formally announced by Japan’s Ministry of Finance shortly after U.S. President Donald Trump stated Sunday that Washington was backing Japan’s efforts to shore up the yen, framing the move as both an act of diplomatic friendship and a measure to support global economic stability. “Japan is dealing with a weakening yen and reached out for some support, and we always stand ready to help our ally Japan,” Trump said in his public comments.
Market reactions to the announcement were immediate and dramatic. The yen jumped 1.4% against the U.S. dollar to hit nearly 155.20 yen per dollar, its highest level in three months. This gain followed a cumulative 3.8% appreciation in the currency across previous trading sessions. The yen also notched significant gains against other major global currencies, including the euro and British pound.
The yen’s sharp upward rally put substantial downward pressure on the U.S. dollar across global markets. During early Asian trading hours, the euro climbed to a six-week high of 1.1559 against the dollar, while the British pound held steady near a two-week peak of 1.3476 against the greenback.
However, the sudden appreciation of the yen also triggered immediate negative repercussions for Japanese equities. Tokyo’s benchmark Nikkei Index swung sharply downward after hitting a one-week high earlier in the trading session, as a stronger yen erodes the international competitiveness of Japan’s key export sector.
Market analysts interpret the joint intervention as a clear signal from both governments that they are determined to prevent the yen’s decline and the volatility in Japanese government bonds from triggering broader instability across global financial markets. The intervention comes as rising yields on U.S. Treasury bonds have already placed mounting strain on currency and equity markets worldwide.
Japan has been grappling with persistent yen weakness for months, a trend that has pushed up import costs, fueled broader domestic inflation, squeezed household budgets, and eroded public support for Japanese Prime Minister Sanae Takaichi’s administration.
According to Japan’s Ministry of Finance, the intervention, carried out jointly with the U.S. Treasury Department on Friday, was launched to counter “excessive volatility and disorderly movements in the yen exchange rate that have unfolded over recent months.” Officials stressed that they “remain on high alert, maintain close communication with our U.S. counterparts, and will not hesitate to undertake additional coordinated intervention measures” if necessary.
This joint currency intervention marks the first coordinated action between the two countries since 2011, when they partnered to weaken the yen in the wake of the devastating Great East Japan Earthquake that disrupted the country’s economy.
Data from the Bank of Japan estimates that Japanese authorities sold up to $58.97 billion worth of U.S. dollars to purchase yen during pre-coordinated intervention activity in New York markets on Thursday, one day ahead of the official public confirmation of the joint action.
U.S. Treasury Secretary Scott Bessent also confirmed the joint intervention, noting that Washington “will not hesitate to participate in further joint actions” if needed. Bessent expressed support for Japan’s efforts to correct the yen’s undervaluation and pushed the Bank of Japan to move forward with upcoming interest rate hikes.
On Friday, the Bank of Japan issued its clearest indication to date that it plans to implement an early interest rate increase, even as it kept its existing monetary policy unchanged for the time being.
In a sign of broader regional coordination to address currency weakness, South Korea also took steps to support its own currency, the won, by intervening in foreign exchange markets on Thursday.
Previous solo interventions by Japan to buy yen in April and May only produced temporary short-term gains for the currency. Even the Bank of Japan’s June interest rate hike, which brought rates to 1% — the highest level in 31 years — failed to deliver sustained support for the yen.