U.S. Treasury Secretary Scott Bessent said that disorderly movements in the yen could trigger rapid reductions of market positions that risk destabilizing global markets and raising borrowing costs for households and businesses. He made the remarks in a letter dated August 27, which he posted on his X account in response to a request from Democratic Senator Elizabeth Warren for details of the United States’ joint currency intervention with Japan in July.

The United States and Japan conducted a rare joint yen‑buying intervention on July 31 to counter a steep decline in the yen and Japanese government bonds. The yen fell to a 40‑year low near 164 per dollar in July before recovering after the intervention, then weakened again toward 160. It briefly slipped below 160 on Friday, a level that market participants view as a trigger for further intervention, after comments from Federal Reserve Chair Kevin Warsh revived expectations of a near‑term U.S. rate hike.

In the letter, Bessent explained that the Treasury used the Exchange Stabilization Fund to exchange foreign‑currency assets for yen during the July 31 operation. He said the same principle was applied in Argentina, where the Fund was used to address short‑term illiquidity and prevent a broader regional crisis. Bessent added that the best‑managed crisis is one that never occurs, defending the decision to cooperate with Tokyo.

The yen remains near 160 against the dollar, and policymakers continue to monitor currency volatility.