The benchmark KOSPI fell more than 3% to around 6,630 on Wednesday, erasing the previous session’s gains as escalating US–Iran tensions drove oil prices higher and dampened global risk appetite. Brent crude climbed above $95 per barrel and WTI surpassed $90, stoking concerns over energy costs and inflation amid the threat of disruptions to oil shipments through the Strait of Hormuz. At the same time, the US 10-year Treasury yield rose to its highest level since January 2025, adding further pressure on equities, particularly technology shares.
Shares of Samsung Electronics and SK hynix declined more than 2% and nearly 3%, respectively. Other notable losers included SK Square (-5.2%), Hyundai Motor (-4.1%), LG Energy Solution (-3.0%), Hanwha Aerospace (-1.9%), Doosan Enerbility (-3.4%), and Kia Corporation (-3.8%).
On the macroeconomic front, South Korea’s annual inflation accelerated to 3.1% in August from 2.8% in July. The government, however, estimated underlying price growth at around 2.5% after excluding a temporary base effect related to mobile phone bills.