The KOSPI rose 2.2 percent to close at 6,615.03 points, after swinging between a low of 6,529.20 and a record intraday high of 6,657.22. Institutions bought 1.10 trillion won (US$747 million) worth of shares, while foreign investors added 888.5 billion Korean won. Retail investors, meanwhile, sold 1.97 trillion won, indicating a rally driven by institutional and offshore flows as risk appetite improved.
Large-cap semiconductor stocks led the rally, buoyed by gains in U.S. tech equities and a sharp rise in the Philadelphia Semiconductor Index. Samsung Electronics climbed 2.3 percent to 224,500 won, while SK Hynix jumped 5.7 percent to 1,292,000 won, after hitting an intraday high of 1,317,000 won as investors bet on a sustained memory upcycle and accelerating AI-driven demand.
Auto-related stocks also stayed firm, with Hyundai Motor rising 2.1 percent to 524,000 won on improving margin expectations, while others showed mixed trends. Doosan Enerbility gained 1.4 percent and HD Hyundai Heavy Industries edged up 0.3 percent, whereas Hanwha Aerospace slipped 0.6 percent amid profit-taking after recent gains.
Battery makers underperformed, with LG Energy Solution falling 3.5 percent to 464,000 won and Samsung Biologics declining 1.2 percent to 1,509,000 won, as investors rotated into semiconductor and cyclical names. Among notable movers, Hyosung Heavy Industries jumped 11.8 percent to 3,971,000 won after brokerages raised target prices on strong North American order momentum, while Korea Zinc ended flat at 1,642,000 won despite progress in its U.S. smelter project.
The junior KOSDAQ rose 1.9 percent to close at 1,226.20, after trading between 1,209.30 and 1,229.40. Institutional investors bought 79.9 billion won and retail investors added 139.9 billion won, while foreign investors sold 180.0 billion won.
Gains on the junior bourse were led by biotech and robotics shares, reflecting continued retail driven momentum in high growth sectors. Alteogen rose 3 percent to 380,000 won, Rainbow Robotics jumped 9.8 percent to 672,000 won and Samchundang Pharm gained 8.6 percent to 447,000 won, while Ecopro edged up 0.1 percent.
Japan's Nikkei 225 also closed at a record high, rising 1.4 percent to 60,537.4, supported by technology gains, ahead of the Bank of Japan's policy decision. Investors widely expect rates to remain unchanged but are watching for any signals on potential tightening as inflation pressures persist.
Elsewhere in Asia, China's Shanghai Composite Index rose 0.2 percent to 4,086.34, while Hong Kong's Hang Seng Index slipped 0.2 percent to 25,922.6, reflecting cautious sentiment as investors balanced strong tech momentum against rising oil prices and geopolitical uncertainty.
Earlier, U.S. markets closed mixed last Friday, with the Dow Jones Industrial Average falling 0.2 percent, while the S&P 500 rose 0.8 percent and the Nasdaq Composite gained 1.6 percent. The Philadelphia Semiconductor Index jumped 4.3 percent, boosting optimism around the global chip cycle and supporting gains in Asian semiconductor shares.
Attention is now turning to a packed global calendar including earnings from major U.S. technology firms and a policy decision from the Bank of Japan, which is expected to provide signals on the future path of monetary policy.
Meanwhile, oil prices extended gains as supply concerns intensified. Brent crude held above US$107 per barrel, up 2.5 percent, while WTI rose 2.2 percent to around $96.5, as stalled U.S.-Iran negotiations and continued disruption in the Strait of Hormuz fueled fears of a prolonged supply shock, raising concerns over inflation and global growth.
The Korean won strengthened against the dollar, with the currency closing at 1,472.1 won, up 0.4 percent from the previous session, supported by renewed foreign inflows into local equities.
Copyright ⓒ Aju Press All rights reserved.