South Korea stocks plunge 8%, circuit breaker triggered as chip shares tumble

The Korea Exchange (KRX) activated a 20-minute circuit breaker at 9:03 a.m. (0003 GMT), temporarily halting all stock and derivatives trading.

The benchmark KOSPI was down around 500 points, or 8.6%, at 4,923.47 as of 0026 GMT.

"It is time for correction, but we feel that there may be some overreaction to the outcome of the midterm election," said Jun Kwang-woo, chairman of the Institute for Global Economics, a financial thinktank in Seoul,

"Hopefully we will stabilise very soon because after all, we understand that the speed of building AI infrastructure, especially data centres may slow down a bit because of the number of concerns in many states including Texas," said Jun, who is a former chairman of South Korea's National Pension Service.

US stock markets suffered their worst single-day session in more than a year on Thursday, led by a sharp unwind in high-flying technology and semiconductor shares.

Fresh uncertainly over policies on AI and data centres following the sweeping gains for the Democratic Party in the US midterm elections sent shockwaves across hardware and chip suppliers.

Shares in South Korean chipmaker Samsung Electronics fell 10%, while peer SK Hynix lost 13%.

Among other index heavyweights, battery maker LG Energy Solution slid 4%, while Hyundai Motor fell 6.9% and sister automaker Kia Corp declined 4%.