[Edaily Reporter Shin Ha-yeon ] On the 5th, the KOSPI extended its intraday decline to the 5% range, falling below the 5,400 mark. As foreign investors’ net selling exceeded 1 trillion won and a sell-off continued—particularly in semiconductor and artificial intelligence (AI) infrastructure-related stocks—the “sell-side car,” which temporarily suspends the execution of program sell orders, was triggered on the KOSPI market. The KOSDAQ index also plummeted nearly 5%, dropping to the 680 level.

According to MP Doctor on the 5th, as of 10:23 a.m., the KOSPI was trading at 5,394.46, down 289.34 points (5.09%) from the previous trading day. This marks the first time in nine trading days—since October 23—that the KOSPI has fallen below the 5,400 level during intraday trading. At that time, the index fell as low as 5,305.98 during the session but recovered its losses to close at 5,550.30. Today, the index opened at 5,580.09 and extended its losses from the start of the session, dropping as low as 5,386.29 during trading. The intraday high was 5,586.46.

As the index plummeted, the sell-side “side car” mechanism was triggered on the stock market today. The KOSPI side car is triggered when the KOSPI 200 futures price remains more than 5% below the benchmark price for at least one minute.

Large-scale selling by foreign investors is dragging down the index. On the stock market, foreign investors are net sellers by 1.039 trillion won. Institutions are also net sellers by 54.5 billion won. In contrast, retail investors are net buyers by 1.0017 trillion won, absorbing the shares sold by foreign investors.

Selling pressure is also intense in program trading. While arbitrage trading shows a net buying position of 120.8 billion won, non-arbitrage trading shows a net selling position of 884.1 billion won, resulting in an overall net selling position of 763.3 billion won.

Among the top market-cap stocks, semiconductor and AI infrastructure-related stocks are seeing particularly sharp declines. SamsungElectronics(005930)is trading at 202,750 won, down 7.00% from the previous trading day, while SK hynix(000660)has plummeted 9.24% to 1,267,000 won. SamsungElectronics(1P)(005935)(-6.17%) and SKSQUARE(402340)(-9.12%) are also falling sharply.

In particular, SamsungElectroMechanics(009150)plummeted 12.02% to 981,000 won. This is believed to be the result of a sharp decline in investor sentiment across the entire AI infrastructure supply chain—including semiconductors and power equipment—as concerns over potential regulations on new data center construction have intensified following the Democrats’ takeover of both the Senate and the House of Representatives in the U.S. midterm elections. Overnight on the New York Stock Exchange, the Philadelphia Semiconductor Index fell 3.13%, while NVIDIA dropped 3.17% and Micron fell 7.00%.

However, sector-specific divergence continues even among the top-market-cap stocks. SAMSUNG BIOLOGICS(207940)is trading at 1,523,000 won, up 1.87%, while HyundaiMotor(005380)is trading at 290,500 won, up 2.47%. KB Financial Group(105560)is also up 3.37%. In contrast, LG Energy Solution(373220)is down 3.24%.

Today’s sharp decline in the domestic stock market runs counter to the overall trend in U.S. markets overnight. Following the U.S. midterm elections, the Dow Jones Industrial Average rose 3.03%, the S&P 500 Index rose 1.58%, and the Nasdaq Composite Index rose 1.44%, driven by expectations of reduced political uncertainty and a reassessment of policy. However, unlike hyperscalers, semiconductor and data center-related stocks are showing weakness due to regulatory concerns, leading to concentrated selling pressure on the domestic AI value chain.

At the same time, the KOSDAQ Index is trading at 680.27, down 34.68 points (4.85%) from the previous trading day. The index opened at 713.49 today and hit an intraday low of 680.27. The intraday high was 717.06.

In the KOSDAQ market as well, foreign investors are leading the decline with net sales of 138.9 billion won. In contrast, retail investors are net buyers of 119.3 billion won, and institutional investors are net buyers of 16.8 billion won. Program trading shows a net buying position of 1.5 billion won in arbitrage trading and a net selling position of 177.8 billion won in non-arbitrage trading, resulting in an overall net selling position of 176.3 billion won.