[Edaily Reporter Kim Hyung-il ] SK hynix(000660)As major semiconductor stocks fell across the board—with some plunging more than 10%—the domestic stock market shifted sharply from buying to selling in just one day. The KOSPI closed down 4.58% after a sell-side “side car” (a temporary suspension of program trading sell orders) was triggered early in the session. A combination of a correction in U.S. semiconductor stocks and selling pressure from foreign investors dragged down the index, led by the top-market-cap semiconductor stocks. In contrast, the KOSDAQ closed higher as stocks with strong earnings momentum performed well.

According to MP Doctor on the 6th, the KOSPI closed at 6,296.38, down 301.88 points (4.58%) from the previous trading day. The KOSDAQ closed at 801.67, up 2.08 points (0.26%). The KOSPI fell sharply by 359.94 points (5.46%) to as low as 6,238.32 during the session but recovered some of its losses toward the end of the trading day.

Early in the session, the decline accelerated rapidly, triggering a sell-side circuit breaker. The Korea Exchange explained that at 10:18 a.m. that day, the price of futures based on the KOSPI 200 had fallen more than 5% below the reference price for over one minute, meeting the trigger criteria. At that time, the Mini KOSPI 200 futures fell 5.04% from the reference price of 1,039.72 points to 987.24 points. Consequently, the effectiveness of sell orders in program trading was suspended for five minutes; at the time of activation, program trading recorded a net sell volume of 843.5 billion won. Following the activation of the buy-side sidecar on the KOSPI the previous day, the sell-side sidecar was triggered just one day later, signaling increased volatility in the domestic stock market.

By investor type, foreign investors led the index decline with net sales of 3.3271 trillion won on the KOSPI market. Retail investors absorbed the selling pressure with net purchases of 3.3390 trillion won, while institutions also recorded net sales of 122.0 billion won. In the KOSDAQ market, foreign investors recorded net sales of 248.2 billion won, while retail investors and institutions recorded net purchases of 85.9 billion won and 161.5 billion won, respectively.

Among the top market-cap stocks, declines were particularly pronounced among semiconductor stocks. SamsungElectronics(005930)fell 6.3%, SK hynix dropped 10.37%, SamsungElectroMechanics(009150)declined 9.37%, and SKSQUARE(402340)fell 13.32%. In contrast, LG Energy Solution(373220)closed up 2.83%, and SAMSUNG BIOLOGICS(207940)rose 1.54%. On the KOSDAQ, Alteogen Inc.(196170)rose 5.96% on news of a technology transfer agreement with a global pharmaceutical company, while ECOPRO CO., LTD(086520)(1.58%), HLB INC.(028300)(0.86%), and ABL Bio Inc.(298380)(3.87%) also posted gains. Conversely, JUSUNG ENGINEERING Co.,Ltd.(036930)(-6.65%) and WONIK IPS Co.,Ltd.(240810)(-5.22%) saw declines.

By sector, the electrical and electronics sector (-7.49%) saw the sharpest decline on the KOSPI, while manufacturing (-5.54%) and medical and precision equipment (-5.32%) also posted losses. Large-cap stocks fell 5.08%, while mid-cap and small-cap stocks rose 1.43% and 0.26%, respectively. On the KOSDAQ, general services (3.48%), pharmaceuticals (2.43%), and food, beverages, and tobacco (1.52%) rose. On the KOSPI, the number of rising stocks (490) exceeded that of falling stocks (381), indicating that rotational trading centered on individual stocks—excluding semiconductors—continued.

Overnight on the New York Stock Exchange, the market showed mixed results, with the Dow Jones Industrial Average hitting a record high, while the S&P 500 and the Nasdaq Composite Index fell. In addition to the weakness in U.S. semiconductor stocks, U.S. NAND flash memory manufacturer #SanDisk plummeted in after-hours trading after presenting guidance that fell short of market expectations despite strong earnings, further dampening domestic investor sentiment toward semiconductors. Consequently, SamsungElectronics(005930)and SK hynix(000660)—which together account for approximately 44% of the KOSPI’s market capitalization—fell in tandem, leading the index lower.

Lim Jeong-eun, an analyst at KB Securities, noted, “In addition to the weakness in U.S. semiconductor stocks, SanDisk’s guidance—which fell short of market expectations despite strong earnings—has dampened investor sentiment toward major domestic semiconductor stocks.” She added, “Non-semiconductor sectors such as cosmetics and banking have shown resilience during the recent correction or maintain valid earnings momentum; therefore, they should be considered as alternative sectors until semiconductor stocks stage a trend-based rebound.”

In fact, APR(278470)rose more than 5% that day after revising its annual revenue guidance upward, while Alteogen Inc.(196170)extended its winning streak to five consecutive trading days on news of a technology transfer agreement with a global pharmaceutical company.