South Korean Won Weakens on Higher US Yields

The South Korean won weakened to around 1,370 per dollar, reversing gains after a sharp rebound, as a surge in US Treasury yields lifted the dollar. The US 10-year Treasury yield climbed to its highest level since July 2007, while stronger-than-expected US economic data heightened inflation concerns and reinforced expectations for further policy tightening. The probability of another 25-basis-point Fed rate hike in October rose to around 70% from 55%, taking the dollar near its strongest level in almost two months. Additionally, oil prices rebounded amid renewed Middle East risks, with Brent crude rising above $103 a barrel, raising concerns over potential supply disruptions and higher import costs for Korea. Meanwhile, the US and China reportedly agreed to extend their trade truce by two months, giving the two sides more time to negotiate a broader agreement and reducing near-term trade uncertainty for Korea’s major trading partners.

The South Korean won strengthened to around 1,351 per dollar, extending its sharp rebound as oil prices continued to fall. US President Donald Trump said a meeting between US and Iranian representatives was “very good,” raising hopes for a diplomatic breakthrough, while oil prices subsequently fell for a sixth straight session, easing inflation concerns and reducing demand for the dollar. Additionally, South Korea’s strong export performance continued to underpin the won, with exports surging 78% year-on-year in the first 20 days of September, driven by a 259% jump in semiconductor exports and boosting dollar inflows. At the same time, the Asian Development Bank raised its 2026 growth forecast for South Korea to 3.2% from 2.6%, citing strong exports and corporate earnings amid the AI boom. However, the dollar remained relatively firm as hawkish Federal Reserve remarks kept markets pricing roughly a 54% chance of another rate hike in October.

The South Korean won strengthened to around 1,355 per dollar, rebounding from four-week lows as oil prices fell sharply. WTI crude declined 4.5% below $100 a barrel, while Brent fell more than 3% amid hopes for progress in US-Iran diplomacy and a recovery in Saudi oil shipments. The US 10-year Treasury yield also fell back below 5% after reaching recent highs last week, easing demand for the dollar. Additionally, South Korea’s strong export performance continued to underpin the won, with exports surging 78% year-on-year in the first 20 days of September, driven by a 259% jump in semiconductor shipments and boosting dollar inflows. Meanwhile, the dollar remained relatively firm as markets monitored the possibility of another Federal Reserve rate increase later this year. Separately, the Bank of Korea said it would assess inflation, growth and financial stability when determining the timing and pace of further rate hikes.