[Edaily Reporter Kim Hyung-il ] Buying momentum in the domestic stock market shifted to selling in just one day. As foreign selling intensified in the wake of profit-taking in U.S. tech stocks, the KOSPI plunged by more than 5% at one point during the session, and the sell-side sidecar (a temporary suspension of sell orders in program trading) was triggered as KOSPI 200 futures prices plummeted.

According to the Korea Exchange on the 6th, a sell-side sidecar was triggered in the KOSPI market at 10:18 a.m. that day. This marks the 46th sidecar triggered so far this year—the 24th sell-side sidecar and the 22nd buy-side sidecar.

The exchange explained that the trigger conditions were met because the price of the nearest-month futures contract based on the KOSPI 200 index remained more than 5% below the reference price for over one minute. The Mini KOSPI 200 futures fell 5.04% from the reference price of 1,039.72 points to 987.24 points. Following the activation, the validity of sell orders from program trading was suspended for five minutes; at the time of activation, program trading recorded a net sell of 843.5 billion won.

On that day, the KOSPI extended its losses from the early trading session as profit-taking in U.S. tech stocks coincided with selling pressure from foreign investors. As of 10:37 a.m., foreign investors had net sold 1.5926 trillion won in the KOSPI market, leading the index lower. In contrast, retail investors and institutions absorbed the selling pressure with net purchases of 1.5308 trillion won and 16.5 billion won, respectively. At one point during the session, the KOSPI fell as low as 6,238.32, plunging 359.94 points (5.46%).

Among the top market-cap stocks, the declines were particularly pronounced in semiconductor stocks. As of 10:30 a.m., SK hynix(000660)was down 9.41%, SamsungElectroMechanics(009150)was down 10.62%, SKSQUARE(402340)was down 10.81%, and SamsungElectronics(005930)was down 6.30%, each leading the index lower. Early in the session, SK hynix’s opening price on the Nextrade (NXT) pre-market was set at 1,168,000 won—a 29.97% drop from the previous trading day—based on just 11 shares traded, triggering the Volatility Interruption (VI) mechanism. Although the decline quickly narrowed afterward, this is believed to be the result of selling pressure concentrated on AI and semiconductor-related stocks, driven by a combination of a correction in U.S. semiconductor stocks and selling by foreign investors.

The previous day, a buy-side sidecar was triggered on the KOSPI, and the KOSDAQ market had also seen buy-side sidecars triggered for three consecutive trading days, signaling a recovery in investor sentiment. However, the fact that a sell-side sidecar was triggered on the KOSPI just one day later indicates that market volatility remains high even amid the recent rebound.