South Korea’s stock market cooled sharply in just one trading session after being among the world’s strongest performers. A combination of rising oil prices due to Middle East tensions and declining global risk appetite triggered heavy profit-taking in the Kospi index, which had led gains this year. The sell-off was amplified by sharp declines in heavyweight stocks.
After a public holiday on Monday provided a brief respite from overseas selling pressure, South Korean equities opened sharply lower on Tuesday. The Kospi index fell more than 7% during the day, triggering a market-wide circuit breaker and prompting regulators to temporarily halt program trading.
Two major heavyweights were at the center of the sell-off. Shares of Samsung and SK Hynix dropped 9.88% and 11.5% respectively, dragging the benchmark to its largest single-day decline since August 2024, when volatility spiked due to an unwinding of yen carry trades.
Risk aversion also spilled into the currency and commodity markets. The Korean won fell 1.34% against the U.S. dollar, which gained support from safe-haven buying. Meanwhile, oil prices rose after the U.S. and Israel launched strikes against Iran on Saturday, putting direct pressure on South Korea, which relies heavily on Middle Eastern crude, and accelerating a market reassessment of previously overheated gains.
Profit-taking intensified following the market’s strong run. As one of the world’s best-performing stock indices in 2026, the Kospi had surged as much as 50% year-to-date by late February. However, after Tuesday’s sharp decline, its gains narrowed to 37%.
Despite the steep drop, South Korean equities still show impressive long-term returns, with a 128% increase over the past 12 months. Still, heightened speculative activity by retail investors last week set the stage for Tuesday’s concentrated sell-off.
Fund flow data indicated that foreign investors had already begun reducing exposure ahead of the decline. According to Korea Exchange figures, international investors recorded a net outflow of 7 trillion won (approximately $47 billion) on the last trading day of February.
Foreign selling continued on Tuesday. Data from Bloomberg and Chosun Biz showed that overseas investors were net sellers again, offloading 5.4 trillion won worth of shares. This foreign selling and the rapid market decline reinforced each other, contributing significantly to the day’s volatility.
The market downturn was not driven solely by internal stock market factors. The weakening Korean won reflected a broader rise in risk aversion, with emerging market currencies under pressure and capital shifting to safe-haven assets like the U.S. dollar.
Rising oil prices had a more specific impact on South Korea. Oil climbed after the U.S. and Israel struck Iranian targets on Saturday. South Korea is one of the world’s largest crude importers, requiring around 2.7 million barrels per day, about 70% of which comes from the Middle East.
Amid the broad market decline, certain themes linked to geopolitical risks gained traction in the South Korean market. Shares of shipping companies such as Korea Line and STX Green Logis, defense stocks like Hanwha Systems and Lig Nex1, and energy-related names such as Daesung Energy all moved higher.
This structural divergence suggests that capital did not simply exit the market but quickly rotated into trades more directly influenced by geopolitical developments amid rising uncertainty.