South Korea's won reaches its strongest level in nine months amid speculation of coordinated Seoul and Tokyo intervention

South Korea's won strengthened sharply against the US dollar on Friday 31 July 2026. According to the Yonhap news agency, the won was quoted at 1,424 per dollar at 3:30 p.m. local time, a gain of 13.4 won from the previous day. The currency had traded at 1,418 per dollar at around 6 a.m., its strongest level since 20 October last year.

The stated driver was net buying by foreign investors in the Korean equity market. In the same trading session foreigners bought a net 7 trillion won ($4.9 billion) of local stocks, and the benchmark Kospi index closed 17.91% higher at 6,595.45. Earlier, in overnight trading, the won had advanced to as much as 1,419 per dollar, with traders speculating that currency authorities had stepped in to smooth the market.

The won's appreciation was in line with a gain in the Japanese yen, which at one point in overnight New York trading rose to about 158 per dollar, its strongest level in more than two years. Moon Ji-sung, South Korea's deputy finance minister for international affairs, told Yonhap that Korea and Japan have maintained close coordination but declined to confirm whether the two countries jointly intervened in the open market. Lee Min-hyuk, an analyst at KB Kookmin Bank, said the correlation between the won and the yen raised speculation that the currency authorities of both countries might have intervened. The path of major Asian currencies and the dollar index is among the variables shaping the world gold price, and through it Tehran's coin and currency market.