Japan, U.S. Near Joint Move to Back Yen as Speculators Push Currency to Multi-Decade Lows

Japan and the United States are expected to signal coordinated support for the yen as early as next week, aiming to deter traders betting on further declines after the currency slid to levels not seen since the mid-1980s. Kyodo News, cited by CNBC, reported that officials in Tokyo and Washington may roll out a formal joint stance within days. Details have not been disclosed, but the move is widely seen as a warning shot to speculative positioning rather than an open-ended commitment to buy yen. The push for coordination follows an unusually volatile stretch in FX markets. On July 30, Japan's Ministry of Finance sold up to $58.97 billion to purchase yen in a single session, central bank data show, delivering the yen's biggest one-day gain versus the dollar since 2022. The currency surged from around 164 per dollar to the upper 150s. U.S. involvement surfaced soon after. A person familiar with the matter said the Treasury Department asked major banks to prepare for the possibility of intervention. The Financial Times later reported the New York Federal Reserve sold euros to buy yen via banks including Goldman Sachs and Morgan Stanley. If confirmed, it would mark Washington's first direct action to support the yen in more than a decade, since the Group of Seven's coordinated response after Japan's 2011 earthquake and tsunami. A Reuters photograph added to expectations of U.S. participation, capturing Treasury Secretary Scott Bessent's notepad during a Camp David cabinet meeting with the handwritten line: "Buy Japanese Yen (JPY) $510 bil." Japan's top currency official Atsushi Mimura said U.S. support went beyond symbolism. The yen's prolonged slide has been driven by the interest-rate gap that opened after 2022, when the Bank of Japan kept rates well below the Federal Reserve's. That divergence fueled the yen carry trade, as investors borrowed cheaply in yen and rotated into higher-yielding dollar assets, lifting import costs for Japanese households. Japan has already tried large-scale intervention this year, spending about 11.73 trillion yen (roughly $73 billion) in April and May. The yen strengthened briefly, then weakened again, a pattern often seen when intervention is not reinforced by a lasting shift in rate policy. Bessent has described the yen as "very undervalued" and warned that excessive volatility is unhealthy for markets. Combined with the reported purchases, the comments point to an uncommon level of currency-policy coordination between the world's largest and fourth-largest economies. A stronger yen could ease pressure on Japanese consumers by lowering the cost of imported energy and food. For U.S. companies and investors, a more stable yen could reduce disruptions to global capital flows. Japan is also one of the biggest foreign holders of U.S. Treasury debt, giving both governments an incentive to avoid disorderly swings that could trigger unplanned selling. Analysts say durability will hinge on fundamentals. Further Bank of Japan rate hikes or Federal Reserve rate cuts would narrow the rate gap that has weighed on the yen and strengthen the impact of any official action. Without that adjustment, markets have historically moved on from verbal commitments and one-off interventions within weeks or months. Traders will be watching for whether the coming announcement sets explicit thresholds for future action, lays out a timeline, or simply reiterates existing cooperation. The timing is expected to be close to a meeting of Group of 20 finance ministers, offering both governments a high-profile venue to underscore a unified message.