Senator Elizabeth Warren asked Treasury Secretary Scott Bessent by Aug. 28 to explain the legal basis, taxpayer cost and any related support for Japan tied to the Trump administration's late-July yen intervention, the first coordinated U.S.-Japan currency operation since June 1998. Bessent has said the United States used euro reserves from the Treasury's Exchange Stabilization Fund, while newer reporting estimated Japan bought $75 billion to $85 billion of yen over two days and said U.S. authorities signaled willingness to use Federal Reserve facilities. The operation briefly pulled dollar-yen from near 164 to the 155 range and triggered a sharp reduction in speculative short-yen positions, but the pair later rebounded to around 159-160, leaving South Korea-listed yen ETFs with weaker or negative 2024 returns than comparable products without yen exposure. Analysts including Park Sang-hyun of iM Securities said further intervention remains possible, citing the Fed's FIMA repo facility, but warned that Japan's fiscal risks, carry-trade dynamics and the limited scope for additional Bank of Japan rate hikes could keep pressure on the yen.