[Edaily Reporter Kwon Oh Seok ] The KOSPI plunged more than 8% shortly after the market opened, breaking below the 5,000 mark. Overnight, the U.S. Nasdaq Index fell more than 5% and the Philadelphia Semiconductor Index plummeted more than 12%, negatively impacting the domestic stock market and ultimately triggering a circuit breaker.

According to MP Doctor on the 6th, the KOSPI opened at 5,263.26, down 120.54 points (2.24%) from the previous trading day. Then, around 9:03 a.m., the first-stage circuit breaker was triggered, and trading was temporarily suspended at 4,923.47, a drop of 460.33 points (8.55%).
The Level 1 circuit breaker is triggered when the KOSPI remains down more than 8% from the previous day’s closing price for one minute, suspending trading for 20 minutes. Level 2 is triggered when the KOSPI falls more than 15% from the previous trading day’s closing price and then drops an additional 1% or more below the Level 1 trigger level, with the decline persisting for one minute. The Korea Exchange explained that this was the 11th time this year and the 17th time in history that the circuit breaker had been triggered.
Earlier, fears swept through the stock market that the policy sentiment in Washington would shift toward “tighter regulation of artificial intelligence (AI)” after the Democrats swept both the U.S. Senate and House of Representatives in the midterm elections. As a result, the U.S. Nasdaq index plummeted by more than 5%, and the Philadelphia Semiconductor Index also crashed by more than 12%.
On the 5th (local time), the Dow Jones Industrial Average closed at 51,523.06 on the New York Stock Exchange (NYSE), down 3.44% from the previous trading day. The S&P 500 Index plummeted 4.36% to 7,353.73, while the tech-heavy Nasdaq Composite Index plunged 5.52% to 24,315.00. The market’s volatility index (VIX) surged 69% in a single day, clearly reflecting widespread panic across the market.
The market decline was led by key stocks in the AI infrastructure value chain. Memory and semiconductor equipment stocks—SanDisk (-22.26%), Western Digital (-17.35%), and Micron (-17.46%)—all collapsed. The Philadelphia Semiconductor Index fell 12.25%.
Consequently, major domestic semiconductor stocks are also being affected. SamsungElectronics(005930)was halted at 181,400 won, down 20,100 won (9.98%) from the previous trading day, breaking the “200,000 won” threshold . SK hynix(000660)was halted at 1,116,000 won, down 148,000 won (11.71%).
Meanwhile, the KOSDAQ index opened at 654.43, down 23.98 points (3.53%) from the previous trading day, and as of 9:25 a.m., it is trading at 631.15, down 47.26 points (6.97%).