Seoul’s stock market extended significant gains amid renewed investor optimism that eased concerns about artificial intelligence (AI) profitability and potential diplomatic progress between the United States and Iran over the Strait of Hormuz. The benchmark Korea Composite Stock Price Index (KOSPI) jumped nearly 4 percent shortly after opening and continued to climb through the morning session.
The advance followed a strong rebound from the previous day’s sharp drop, signaling increased confidence in the market’s trajectory. The Korea Exchange briefly triggered a buy-side sidecar mechanism to moderate the rapid surge driven primarily by tech stocks, indicating heightened trading activity. The atmosphere also reflected global market moves, with U.S. equities rising on bets that reopening the critical shipping lane could ease oil prices and inflation pressures.
Tech sector strength fueled much of the rally in Seoul. Samsung Electronics and chipmaker SK hynix led the gains, rising over 2.5 percent and 5.5 percent respectively. Other major companies, including Hyundai Motor and Korean Air, recorded notable increases as positive earnings reports and easing fears about heavy AI investment boosted sentiment across industries. Meanwhile, refining companies like SK Innovation and S-Oil lagged amid mixed energy market signals.
Institutional and foreign investors showed strong net buying activity, investing hundreds of billions of won in local stocks, even as retail investors moved to sell shares. This activity highlights differentiated confidence levels across investor groups, with the foreign inflows supporting the KOSPI’s upward momentum.
Additionally, a central bank report highlighted growing foreign tourist spending in South Korea, which reached more than one percent of the country’s gross domestic product in 2025. This reflects a broader recovery in inbound travel and could further support economic prospects amid the market rally.