On the 10th, the KOSPI and KOSDAQ indexes rebounded sharply by 2.5% and 5.5%, respectively, to end the session. Strength in U.S. New York stock market semiconductor shares warmed Korea's market, and net buying by institutions added to the rally.
The KOSPI index closed at 7,475.94, up 184.03 points (2.52%) from the previous session. After opening at 7,552.49, up 260.58 points (3.57%) from the day before, the KOSPI gave back some gains in the afternoon. Then, at 12:54 p.m., strong institutional buying emerged, triggering this year's 17th temporary suspension of program buy quotes (buy sidecar) on the Korea Exchange's main board.
On the main board, individuals and foreigners were net sellers of 772.8 billion won and 322.6 billion won, respectively, while institutions alone were net buyers of 1.1319 trillion won, lifting the index.
Among large-cap names on the main board, bellwether Samsung Electronics(005930) rose 2.52% from the previous session to finish at 285,000 won. SK Square(402340) added 6.18% to 1,409,000 won, and Samsung Electro-Mechanics(009150) climbed 6.10% to 1,584,000 won. Hyundai Motor(005380) (2.69%), LG Energy Solution(373220) (3.99%), and Samsung Biologics(207940) (5.28%) also staged rallies.
Gains were also notable in financials KB금융 (7.58%) and Shinhan Financial Group(055550) (4.00%), and in nuclear power names such as Doosan Enerbility(034020) (6.69%).
By contrast, SK hynix(000660), which had climbed early in the session, finished down 0.27% at 2,180,000 won as profit-taking emerged.
The KOSDAQ market maintained momentum into the late session and posted an explosive rally. The KOSDAQ index ended at 837.43, up 43.43 points (5.47%) from the previous session. The market also saw this year's 12th buy sidecar triggered at 1:08 p.m.
In KOSDAQ flows, individuals and foreigners were net sellers of 475.4 billion won and 117.3 billion won, respectively, while institutions were net buyers of 587.3 billion won, driving the index higher.
The sharp improvement in investor sentiment came from positive developments in U.S. tech and semiconductor sectors the day before.
Micron, in particular, surged after unveiling plans to make large-scale investments in U.S. production facilities to meet AI demand. Major semiconductor technology stocks, including Meta, which disclosed its own AI chip plan, and Lam Research, also advanced together, helping restore investor sentiment in the domestic market.
The previous day, the Standard & Poor's (S&P) 500 rose 0.81% from the prior session, the Nasdaq gained 1.30%, and the Dow Jones Industrial Average added 0.27%.
Lee Kyung-min, a Daishin Securities researcher, said, "Concerns surrounding the semiconductor cycle eased on the back of investment plans by Meta and Micron, improving investor sentiment," adding, "solid investment demand confirmed for SK hynix American depository receipts (ADR) also supported semiconductor investment sentiment and acted as upward pressure on the market."