The U.S. Treasury has informed major banks that it may intervene in the Japanese yen market on Friday, signaling a potential coordinated effort with Tokyo to stabilize a currency that has sunk to four-decade lows against the dollar. The notice, channeled through the Federal Reserve Bank of New York, tells banks to “stand ready for future action,” according to a source familiar with the matter.
The Treasury’s warning comes a day after Japanese authorities executed what analysts described as a surprise intervention on July 30, pushing the yen up more than 3 percent to as strong as 157.8 to the dollar—its biggest single-day move since 2022. The currency had been languishing near 164 yen per dollar, a level not seen in roughly four decades.
The yen’s persistent weakness has become a growing economic concern for Japan. A weaker currency drives up import costs, exacerbating the impact of rising energy prices on Japanese consumers and businesses. Japan’s government, led by Prime Minister Sanae Takaichi, has signaled that the weak yen is starting to harm the broader economy and has warned repeatedly for months that it would intervene without advance notice.
Treasury Secretary Scott Bessent told Fox Business Network on Thursday that the yen “seems very undervalued to me” and praised Japanese Prime Minister Takaichi’s “strong policies.” He added that “excess volatility in the yen isn’t healthy” and that the currency has “substantially overshot what would be called an equilibrium price.”
Japan’s top currency diplomat, Atsushi Mimura, hinted Friday at deeper U.S. involvement in the effort, noting that American support “goes beyond psychological support.” The Federal Reserve maintains a dollar liquidity swap line with the Bank of Japan and four other major central banks, a tool that could facilitate coordinated action.
Precedent: April-May Intervention and Its Limits
This potential U.S. intervention would mark a significant escalation. Japan spent a record 11.7 trillion yen—approximately $73 billion—on yen-buying intervention over April and May 2026, the largest monthly intervention in the nation’s history. Yet despite that massive effort, the yen soon gave back those gains and resumed its decline, illustrating the challenge of sustaining currency support against deep structural market pressures.
The last time the United States directly intervened to prop up the yen was in March 2011, when the Federal Reserve and other G7 countries coordinated action to stabilize the currency after a devastating earthquake and tsunami. A direct U.S. Treasury intervention now would signal renewed concern about yen weakness and its spillover effects on global financial stability.
News of the potential U.S. intervention helped push the yen higher on Friday, with the currency trading at 159.09 to the dollar, up sharply from Thursday’s lows. Market participants remain on high alert for further intervention, with analysts noting that the Treasury’s notice to banks adds to expectations of additional action.
Sources
- Reuters — Treasury notification to banks, the July 30 yen surge, and Bessent’s comments on yen valuation
- Reuters — History of Japan’s interventions and the April-May 2026 $73 billion intervention record
- Reuters — Last U.S. yen intervention in 2011 and swap line details
