Japan confirmed a historic joint intervention with the US to support the struggling yen, with finance minister Satsuki Katayama stating on Monday that the coordinated action countered excessive volatility. This marked the first time in nearly 30 years the two nations joined forces for outright yen purchases after the currency hit its weakest level against the dollar since 1986.

The yen, which had approached ¥164 in July, strengthened rapidly to ¥155.50 following suspected deployment of ¥8.45tn ($52.8bn) on Thursday and further intervention Friday. Satsuki Katayama vowed authorities would not hesitate to conduct additional joint operations if disorderly movements persist.

US Treasury secretary Scott Bessent affirmed the coordination, pledging continued participation. Analysts Yujiro Goto of Nomura and Masayuki Nakajima of Mizuho interpreted the moves as a strong commitment to a stronger yen, with Nakajima noting US concerns about spillover effects on global bond markets, including Treasuries.

Bank of Japan governor Kazuo Ueda signaled potential rate hikes to avoid falling behind the curve, while President Donald Trump characterized the intervention as yielding financial benefit for the US and supporting the global economy.