[Edaily Reporter PARK MIN ] The KOSPI index, which had attempted a rebound buoyed by gains in U.S. semiconductor stocks, ultimately closed lower on the 9th after a seesaw battle around the 5,100 level. The KOSPI, which had plummeted more than 11% over the past week, began to rebound thanks to large-scale net buying by institutional investors. However, a flood of selling by foreign and retail investors in the latter part of the session wiped out all of the gains, causing the index to close just above the 5,010 level.

According to MP Doctor on the 9th, at 3:33 p.m. that day, the KOSPI index closed the regular session at 5,018.85, down 40.84 points (0.81%) from the previous trading day. The KOSPI got off to a shaky start, slipping as low as 4,995.21 early in the session, but strong buying at lower levels pushed it up to 5,172.94 at one point during the session. However, as foreign selling intensified in the afternoon, the index reversed course and closed just above the 5,010 mark.

In terms of supply and demand, a barrage of selling by foreign investors weighed on the index. Although institutions alone made net purchases of 863.7 billion won to defend against the sell-off, they were unable to offset the net selling by foreign investors and retail investors. On this day, foreign investors sold a net 864.7 billion won, and retail investors sold a net 461.7 billion won, dragging the index down. Notably, net selling by foreign investors continued for the seventh consecutive trading day.

Although the U.S. stock market in New York saw a strong rebound over the weekend—with the Philadelphia Semiconductor Index rising 4.21%—the rebound in the KOSPI market was limited due to continued selling by foreign investors. The extramarital affair scandal involving Jensen Huang, CEO of NVIDIA, also heightened uncertainty in the stock market.

Lee Kyung-min, an analyst at DaishinSecurities, noted, “Although the KOSPI index attempted a rebound, led by the semiconductor sector, as bargain-hunting emerged following the recent sharp short-term decline, the upward momentum was limited due to net selling by foreign investors.”

SK hynix(000660), which had risen more than 4% during the session, closed just above 1,136,000 won, up 0.35% (4,000 won), while SamsungElectronics(005930), which had shown upward momentum in the 2% range, also closed at 189,900 won, up 0.64% (1,200 won). SamsungElectronics(1P)(005935)rose 0.40% to 150,900 won.

Most large-cap non-semiconductor stocks ended the day in the green. LG Energy Solution(373220), a leading battery stock, closed at 318,000 won, down 5.78% (19,500 won) from the previous trading day, while SamsungElectroMechanics(009150)(-3.10%) and HyundaiMotor(005380)(-2.86%) also fell sharply. In addition, Celltrion(068270)(-0.47%), SAMSUNG BIOLOGICS(207940)(-0.40%), SKSQUARE(402340)(-0.28%), and KB Financial Group(105560)(-0.07%) all turned lower.

At the same time, the KOSDAQ index also surged to the 658 level during the session but, lacking momentum, closed at 638.97, down 5.30 points (0.82%) from the previous trading day. In the KOSDAQ market, institutional investors were net buyers of 109.2 billion won, while foreign and retail investors were net sellers of 80.3 billion won and 35.6 billion won, respectively.

Among the top-market-cap stocks on the KOSDAQ, the market saw extreme polarization. Semiconductor materials, parts, and equipment stocks—such as SIMMTECH Co., Ltd.(222800)(up 6.84%), JUSUNG ENGINEERING Co.,Ltd.(036930)(up 6.70%), and EO Technics Co., Ltd.(039030)(up 6.00%)—performed well, maintaining sharp gains in the 6% range.

In contrast, Alteogen Inc.(196170), the company with the largest market capitalization, closed at 168,400 won after plummeting 16.01% (32,100 won) in the wake of the finalization of U.S. regulations regarding drug price negotiations. ECOPRO BM CO., LTD.(247540)(-8.66%) and ECOPRO CO., LTD(086520)(-8.46%), both manufacturers of lithium-ion battery cathode materials, also plunged by around 8%, while Rainbow Robotics(277810)(-5.76%) and HLB INC.(028300)(-3.52%) also saw their shares drop sharply.

Securities analysts predicted that last week’s rebound in the U.S. Philadelphia Semiconductor Index and the perception that the KOSPI’s forward price-to-book ratio (PBR) had hit a record low of 0.95x were stimulating bargain-hunting by institutional investors.

However, with major macroeconomic and AI earnings events on the horizon—including the U.S. October Consumer Price Index (CPI) on the 10th (local time) and CoreWeave’s earnings announcement on the 11th—foreign investors’ net selling of spot stocks continues. Consequently, many analysts believe that any further upward movement in the index depends on whether foreign investor sentiment shifts.

Han Ji-young, an analyst at KIWOOM Securities, said, “Unless new negative factors emerge on the macroeconomic or artificial intelligence (AI) fronts, we do not expect a repeat of last week’s chain reaction of sharp declines,” adding, “The key going forward will be the extent to which the market can recover from last week’s losses, and this will primarily depend on the major macroeconomic and AI earnings events scheduled for this week.”