Screens at Hana Bank's main dealing room in Jung District, Seoul, display the KOSPI and other market indicators on Nov. 6, 2026. A circuit breaker was triggered after the KOSPI plunged more than 8% in early trading. /Yonhap

South Korea's benchmark KOSPI index plunged more than 8% shortly after the market opened Friday, falling below the 5,000-point mark. The sell-off, which followed a drop of more than 5% the previous day, triggered a circuit breaker that temporarily halted trading on the main stock market.

According to the Korea Exchange (KRX), a first-stage circuit breaker was triggered at around 9:03 a.m. after the KOSPI fell more than 8% from the previous session's close. Trading in stocks listed on the main market was consequently suspended for 20 minutes. It was the 10th time a circuit breaker had been triggered on the KOSPI market this year.

A circuit breaker is a market stabilization measure activated when a stock index remains at least 8% below its previous closing level for one minute or longer. When a first-stage circuit breaker is triggered, stock trading is suspended for 20 minutes.

The sharp decline appeared to reflect a broader sell-off in U.S. equities, particularly technology stocks. Following the Democratic Party's victory in the U.S. midterm elections, concerns have grown that investment in artificial intelligence (AI) data centers could face new obstacles, weighing on investor sentiment toward South Korea's major semiconductor stocks.

The KOSPI had closed Thursday at 5,383.80, down 300.00 points, or 5.28%, from the previous session. Semiconductor stocks led the decline, with Samsung Electronics plunging 7.57% and SK hynix tumbling 9.46%. The second consecutive day of steep losses has further heightened volatility in South Korea's stock market.

                                                                                                               Park Ju-yeon