US Treasury joins Japan in buying yen in first joint currency intervention in more than a decade

Summary

The US Treasury Department bought yen on August 1 in a coordinated move with Japan's Ministry of Finance, marking the first joint US-Japan currency intervention in more than a decade. Nikkei Asia reported that a leaked document showed Treasury Secretary Scott Bessent had planned to buy US$5bn to US$10bn of yen. CNBC confirmed the operation and noted the Japanese Yen was near 40-year lows. The previous evening, the US Treasury had warned banks that further intervention was possible and to prepare for a potential yen-buying operation. The Bank of Japan held its benchmark rate at 1% on July 31.

The split

Nikkei Asia led the coverage with the Bessent document leak, giving the most specific figure on the scale of the operation. CNBC focused on the historical rarity of US intervention. Neither outlet reported an official US Treasury comment confirming the operation, relying on the Financial Times as the primary source.

By the numbers

• US$5bn to US$10bn, planned yen purchase according to Bessent document, Nikkei Asia reported.
• Yen near 40-year lows at the time of the intervention.
• First US-Japan joint currency intervention in more than a decade, per CNBC.
• Bank of Japan held its benchmark rate at 1% on July 31.

Why it matters

A joint US-Japan currency operation is rare and signals both governments are treating yen weakness as a shared problem rather than a bilateral trade irritant. It breaks from the usual division where Japan intervenes alone and US administrations stay out. Markets will watch whether the intervention holds or whether further action follows.

What to watch

• Whether the yen stabilises or the intervention effect fades, triggering further rounds.
• Any official US Treasury statement confirming or denying the operation.
• How the Bank of Japan's rate path interacts with currency intervention going forward.