US and Japan Step In to Halt Yen's Slide in First Joint Intervention Since 2011

US and Japan Intervene as Yen Hits 40-Year Low

The United States and Japan carried out a coordinated currency intervention last week, buying yen after the Japanese currency tumbled to a fresh 40-year low against the US dollar. It was the first time Washington joined Tokyo in buying yen since 2011, when the two governments acted together after the earthquake and tsunami that devastated eastern Japan.

Japan’s Ministry of Finance said the operation, conducted with the US Treasury Department, “countered excessive volatility and disorderly movements” in the yen in recent months. Treasury Secretary Scott Bessent echoed that language in a social media post, saying the “coordinated foreign exchange actions countered disorderly yen movements.” He added that the US “strongly supports Japan’s decisive market and monetary steps to correct the substantial undervaluation of the yen.”

Neither government disclosed the size of the intervention. President Donald Trump, asked about the operation aboard Air Force One, told reporters that Japan has “a weakening yen, and they wanted a little bit of help. And we’re always there for Japan.” Both Japan’s Ministry of Finance and Secretary Bessent have said they will not hesitate to conduct further joint interventions if needed.

The move matters because coordinated yen-buying by the US and Japan is extremely rare and signals that both governments now view the yen’s decline as more than a simple market adjustment. The question markets are now weighing is whether the intervention can reverse the currency’s slide or only slow it.

Why the Joint Yen Intervention Matters — and Its Limits

The joint intervention is as notable for who took part as for what it did. Direct currency intervention by the US is uncommon, and the last American participation in yen-buying came during the disaster-driven market turmoil of 2011. By acting together, Washington and Tokyo have turned a Japanese exchange-rate problem into a shared policy priority.

Why Washington Joined Tokyo

Bessent’s reference to a “substantial undervaluation” of the yen is significant because it frames the intervention as a correction of a misaligned exchange rate rather than simply a response to short-term volatility. That framing gives Washington political and economic cover for selling dollars to buy yen, a step US administrations have historically been reluctant to take. Trump’s public reassurance that the US is “always there for Japan” also signals that the decision had support at the highest political level, reducing the risk that this remains a one-off action.

What the Intervention Can and Cannot Change

Currency intervention works by shifting supply and demand in the foreign-exchange market, but it does not by itself change the underlying forces that have pushed the yen down. The yen’s slide has been driven primarily by the wide gap between US interest rates and Japan’s ultra-low rates, which makes dollar-denominated assets more attractive. Unless market participants begin to expect a change in that rate differential, the pressure on the yen is likely to persist.

Still, the official language about “disorderly movements” matters. Both governments have effectively declared a threshold for future action: if the yen weakens rapidly again, they have said they are prepared to intervene. That threat alone can influence speculative positioning, even if it does not immediately change the trend.

Who Gains and Who Loses

A stronger yen would ease the pain for Japanese households and businesses that have faced rising import costs for energy, food and raw materials. It would also help Japanese companies that buy inputs from abroad but sell in domestic yen. On the other side, Japan’s major exporters, which have benefited from a weak yen through cheaper goods in foreign markets, could see their overseas earnings lose value when converted back into yen.

For US-based importers of Japanese goods, yen appreciation means Japanese products become more expensive in dollar terms. For US exporters selling into Japan, a stronger yen makes American goods cheaper for Japanese buyers, potentially supporting US sales. Multinationals with large yen-denominated revenue or costs, including automakers and electronics firms, face the most immediate earnings sensitivity.

What to Watch Next

The most important signals will come from Tokyo and Washington. Japan’s Ministry of Finance typically releases intervention data with a lag, so the market may not know the exact scale of last week’s operation for some time. Investors will also watch for any new statements from Bessent or Japanese officials repeating their willingness to act, as well as any shift in Bank of Japan policy expectations that could reduce the interest-rate gap pressuring the yen.

How to Position for More Yen Interventions

For corporate treasurers, finance executives and investors with exposure to USD/JPY, the intervention changes the risk picture even though the size of the operation is unknown. Key considerations:

• Treasury Secretary Bessent and Japan’s Ministry of Finance have both said they will not hesitate to act again, so this should be treated as an active intervention regime rather than a one-off event.
• The size of the US purchase has not been disclosed, and until Japan publishes its official intervention figures the market will not know how much firepower was actually used.
• Companies with yen-denominated revenue or costs should review their hedging positions, since the first US yen-buying since 2011 shows that a prolonged one-way yen decline can be interrupted abruptly.
• Importers of Japanese goods should watch for near-term cost increases if the yen strengthens further, while exporters to Japan may gain a pricing advantage.
• President Trump’s public support for the operation suggests political backing for repeat intervention, increasing the likelihood of further coordinated action if the yen weakens sharply again.
• Markets will treat the phrase “excessive volatility and disorderly movements” as a trigger signal, so companies should monitor official statements for that language.