[Edaily Reporter KIM YOON-JEONG ] The KOSPI opened up more than 2% on the 13th and surpassed the 5,500 mark during the session, but closed lower as foreign selling intensified. Despite the shock of former NVIDIA CEO Jensen Huang’s resignation, the market continued its upward trend in the morning, buoyed by expectations for growth in the artificial intelligence (AI) industry. However, in the afternoon, selling pressure emerged, particularly in large-cap semiconductor stocks, causing the index to give up all its gains.

According to MP Doctor, the KOSPI closed at 5,290.53, down 52.20 points (0.98%) from the previous trading day.
The index opened at 5,452.41, up 109.68 points (2.05%) from the previous trading day. At one point during the session, it rose as high as 5,504.44, with the gain exceeding 3%. However, it turned downward in the afternoon, falling as low as 5,259.09 during the session before closing after partially recovering.
On the stock market, foreign investors led the decline with net sales of 547.5 billion won. In contrast, retail investors and institutions recorded net purchases of 17.2 billion won and 2.4 billion won, respectively.
Most of the top-market-cap stocks were generally weak. SamsungElectronics(005930)closed regular trading at 206,000 won, down 2,000 won (0.96%) from the previous trading day. SK hynix(000660)closed at 1,216,000 won, down 38,000 won (3.03%). Both stocks rose early in the session before turning lower.
In addition, SKSQUARE(402340)(-3.67%), SamsungElectroMechanics(009150)(-3.50%), SAMSUNG BIOLOGICS(207940)(-2.62%), and LG Energy Solution(373220)(-1.52%) also fell. On the other hand, KB Financial Group(105560)(4.74%), Celltrion(068270)(2.15%), SamsungElectronics(1P)(005935)(1.31%), HyundaiMotor(005380)(1.13%), and Samsung Life Insurance(032830)(0.80%) rose.
Overnight, the New York stock market fell across the board amid the shock of NVIDIA CEO Jensen Huang’s resignation and concerns over rising international oil prices and U.S. Treasury yields. NVIDIA’s stock price plummeted by as much as 14% early in the session before paring its losses to close down 4.34%. In contrast, competitors AMD and Broadcom each rose by around 5%, reflecting expectations of a shifting competitive landscape within the AI semiconductor industry.
Buoyed by these expectations, the domestic stock market also showed strength through the morning, led by large-cap semiconductor stocks. However, as the afternoon progressed, net selling by foreign investors intensified and macroeconomic concerns—such as rising U.S. Treasury yields—came to the fore, causing the KOSPI to turn downward.
Lee Kyung-min, an analyst at DaishinSecurities, noted, “The KOSPI opened higher but turned bearish during the session as net selling by foreign investors intensified.” He added, “In the absence of any clear new negative factors, volatility increased due to supply-and-demand conditions as AI-related uncertainties and macroeconomic pressures persisted.”
The rise in the U.S. 10-year Treasury yield to the 5.1% range also acted as a headwind. Analysts attribute the decline in investor sentiment to a combination of rising international oil prices driven by geopolitical tensions in the Middle East and hawkish remarks from U.S. Federal Reserve (Fed) officials.
Furthermore, the analyst assessed, “Since no immediate activation of the Stock Market Stabilization Fund or concrete implementation plan was presented, it was insufficient to meet expectations for short-term market stabilization measures.” Earlier that morning, at a policy roundtable titled “A Trusted Capital Market: Asking Questions and Finding Answers on the Ground,” presided over by President Lee Jae-myung at the Korea Exchange in Yeouido, Seoul, policy ideas were discussed, including the activation of the stock market stabilization fund, strengthening shareholder returns, restructuring the KOSDAQ market, and measures to expand long-term investment capital.
The KOSDAQ market closed higher. The KOSDAQ index ended the day at 699.66, up 3.13 points (0.45%) from the previous trading day. The index opened at 705.96, up 9.43 points (1.35%), and rose as high as 725.81 during the session, but gave up most of its gains to close below the 700 mark.
In the KOSDAQ market, institutional investors were net buyers of 126.2 billion won. In contrast, retail investors and foreign investors were net sellers of 56.3 billion won and 72.2 billion won, respectively.
Top-market-cap stocks showed mixed performance. Alteogen Inc.(196170), the top-ranked stock by market capitalization, closed at 176,200 won, down 1,200 won (0.68%) from the previous trading day. ECOPRO CO., LTD(086520), ranked second, closed at 72,700 won, up 300 won (0.41%).
In addition, Rainbow Robotics(277810)(5.21%), ECOPRO BM CO., LTD.(247540)(1.00%), SIMMTECH Co., Ltd.(222800)(0.73%), and JUSUNG ENGINEERING Co.,Ltd.(036930)(0.29%) all rose. On the other hand, HLB INC.(028300)(-2.89%), EO Technics Co., Ltd.(039030)(-2.72%), WONIK IPS Co.,Ltd.(240810)(-1.89%), SAM CHUN DANG PHARM CO. LTD(000250)(-1.76%), and LEENO Industrial Inc(058470)(-1.71%) all fell.