[Edaily Reporter KIM YOON-JEONG ] The KOSPI is fluctuating around the 5,700 mark on the afternoon of the 21st. As investor sentiment improves following strong earnings reports from U.S. artificial intelligence (AI) companies, major semiconductor stocks such as SamsungElectronics and SK hynix are leading the index’s rebound. A buy-side circuit breaker was also triggered on the stock market this morning.

According to MP Doctor, as of 2:09 p.m. today, the KOSPI stood at 5,696.07, up 143.33 points (2.58%) from the previous trading day. The index opened at 5,666.34, up 113.60 points (2.05%) from the previous close, and rose as high as 5,816.43 during the session.
At approximately 10:51:56 a.m. today, the effectiveness of program buy orders on the stock market was suspended for five minutes due to a sharp surge in KOSPI 200 futures prices. At the time of activation, the KOSPI 200 futures index stood at 904.84, up 44.94 points (5.22%) from the previous trading day’s closing price. The KOSPI buy-side sidecar is triggered when the KOSPI 200 futures price remains more than 5% above the benchmark price for one minute.
In the stock market, foreign investors and institutions are net buyers of 432.1 billion won and 47.2 billion won, respectively. In contrast, retail investors are net sellers of 1.0139 trillion won.
Strong earnings from U.S. AI-related companies are cited as the reason behind today’s rebound. Kang Jin-hyuk, an analyst at Shinhan Investment Securities, explained, “SpaceX posted a surprise with revenue up 161% year-over-year, and AI revenue surged 830% to account for more than half of total revenue.” He added, “The sharp growth in Superintelligence (SI)-related revenue—shifting away from the previous reliance on STACO LINK’s cash flow—has alleviated market concerns regarding large-scale capital expenditures.”
He further noted that Supermicro Computer also bolstered investor sentiment toward AI infrastructure-related stocks by announcing preliminary revenue (between $18.5 billion and $19.5 billion) that exceeded market expectations.
Strong domestic semiconductor exports are also cited as a positive factor. According to analysis, total exports from the 1st to the 20th of this month rose 105.4% year-over-year, while semiconductor exports surged 222.5%.
Most sectors are showing strength. Medical and precision equipment led the gains with a 5.67% rise, while electrical and electronics (3.85%), manufacturing (3.02%), general services (1.91%), construction (1.85%), and distribution (1.83%) are also on the rise. In contrast, metals (-1.97%), telecommunications (-1.88%), and textiles and apparel (-1.22%) are trading lower.
Among the top stocks by market capitalization, SamsungElectronics(005930)—the company with the largest market cap—is trading at 221,500 won, up 10,000 won (4.73%) from the previous trading day. SK hynix(000660), the second-largest by market cap, is trading at 1,277,000 won, up 54,000 won (4.42%).
In addition, SAMSUNG C&T CORPORATION(028260)(4.91%), SKSQUARE(402340)(3.24%), SamsungElectronics(1P)(005935)(2.77%), Samsung Life Insurance(032830)(2.53%), SAMSUNG BIOLOGICS(207940)(2.37%), and SamsungElectroMechanics(009150)(0.52%) are also showing gains. On the other hand, LG Energy Solution(373220)(-0.48%), HyundaiMotor(005380)(-0.16%), and KB Financial Group(105560)(-0.06%) are trading lower.
At the same time, the KOSDAQ Index stands at 791.21, up 9.24 points (1.18%) from the previous trading day. The index opened at 793.40, up 11.43 points (1.46%) from the previous close, and rose as high as 803.68 during the session.
In the KOSDAQ market, institutional and retail investors are net buyers of 78.2 billion won and 59.7 billion won, respectively. Foreign investors are net sellers of 145.7 billion won.
Alteogen Inc.(196170), the company with the largest market capitalization, is trading at 237,000 won, up 6,000 won (2.60%) from the previous trading day. ECOPRO CO., LTD(086520), the company with the second-largest market capitalization, is trading at 83,700 won, up 300 won (0.36%).
SAM CHUN DANG PHARM CO. LTD(000250) ECOPRO BM CO., LTD.(247540)(3.41%), (3.04%), (2.22%), (1.16%), (1.05%), (0.83%), and (0.13%) are also rising. In contrast, (-1.40%) and (-0.74%) are falling. JUSUNG ENGINEERING Co.,Ltd.(036930) WONIK IPS Co.,Ltd.(240810) SIMMTECH Co., Ltd.(222800) EO Technics Co., Ltd.(039030) Rainbow Robotics(277810) HLB INC.(028300) LEENO Industrial Inc(058470)