On the 20th, the KOSPI index inched up and reclaimed the 5,780 level. Foreign investors were net sellers, but individuals and the national pension funds were net buyers. The KOSDAQ index rose more than 1.5%, with Sam Chun Dang Pharm surging more than 10% to become the KOSDAQ "bellwether" (No. 1 by market cap).
The KOSPI closed at 5,781.20, up 17.98 points (0.31%) from the previous session. After climbing to the 5,830 level and showing gains of more than 1% intraday, the KOSPI pared gains as selling by foreign investors intensified during the session.
Individuals bought 2.5756 trillion won and institutions bought 94.1 billion won in the main board. Foreign investors alone were net sellers worth 2.7170 trillion won.
In particular, foreign investors maintained a "sell" stance in the futures market for seven straight sessions. On the day, foreign investors were net sellers of 3,286 contracts of KOSPI200 futures.
Most top market-cap stocks were weak. Doosan Enerbility (3.10%), LG Energy Solution (1.21%) and Samsung Biologics (1.01%) rose, but Hanwha Aerospace (-4.00%), Kia (-1.17%), Hyundai Motor (-0.96%), SK hynix (-0.59%) and Samsung Electronics (0.55%) fell.
The KOSDAQ index ended at 1,161.52, up 18.04 points (1.58%) from the previous session. Unlike on the main board, foreign investors were net buyers on the KOSDAQ to the tune of 218.0 billion won. Individuals and institutions sold 100.9 billion won and 92.2 billion won, respectively.
In particular, Sam Chun Dang Pharm soared more than 14% on the day to take the top spot in KOSDAQ market cap. News that it filed a clinical trial application (CTA) for a candidate oral insulin led to the stock's rise.
Sam Chun Dang Pharm, which was No. 3 until the previous day, saw its market cap swell to 21.2760 trillion won, leapfrogging EcoPro (20.4886 trillion won) and Alteogen (18.9242 trillion won).
Most of the other top KOSDAQ market-cap names also flashed red. Peptron rose nearly 9%, and LigaChem Biosciences posted gains of more than 6%. EcoPro BM (1.16%), Kolon TissueGene (1.03%) and ABL Bio (0.26%) also ended higher. Rainbow Robotics (-8.22%) and LEENO Industrial (-4.61%) were weak.
Kang Jin-hyuk, an analyst at Shinhan Investment & Securities, said, "Even as the KOSPI rebounded, foreign selling continued, while large-cap biotechs pulled up the KOSDAQ index," and noted, "With the end of the world's largest artificial intelligence (AI) conference, 'GTC 2026,' and Micron's earnings, a wave of profit-taking hit physical AI-related stocks."