Won Rides US-Japan Intervention Wave as Seoul Stays Muted

The U.S.-Japan currency intervention has sent shockwaves across Asia, with the Korean won emerging as one of its biggest beneficiaries. According to an AJP analysis of closing exchange rates, the yen appreciated 3.67 percent against the dollar between July 29 and Aug. 5, but after Washington joined Tokyo on July 31, the picture shifted.

The won strengthened 1.45 percent through Aug. 5, while the yen was little changed, suggesting the intervention's immediate impact faded as broader regional positions adjusted. The sequence points to a two-stage market response: the yen received the initial lift, while the unwinding of yen-funded carry trades and broader repositioning across Asian currencies produced a stronger tailwind for the won.

Beijing has condemned the operation as a self-serving bargain that is unlikely to alter the yen's long-term decline. Chinese state media and market analysts argued the operation was driven less by alliance solidarity than by Washington's own economic interests, saying it would protect U.S. manufacturers and Treasury market while shifting much of the economic cost onto Japan.