Nikkei and Kospi plunge after US tech sell-off

Japanese and South Korean shares fell on Friday after a US technology sell-off linked to concern over the outlook for artificial intelligence data centre investment.

Tokyo's Nikkei 225 index dropped 5.1 percent to 56,930 points in early trade. Seoul's Kospi fell 8.5 percent to 4,923, triggering a circuit breaker that suspended trading for 20 minutes.

The US tech-focused Nasdaq finished 5.5 percent lower overnight, its worst percentage-loss session since April 2025. The sell-off hit Nvidia and other semiconductor stocks.

In South Korea, Samsung Electronics fell nearly 10 percent and SK hynix dropped more than 11 percent. In Japan, Tokyo Electron traded about nine percent lower and Kioxia shed 13 percent.

Online brokerage Monex said concerns about stricter regulation of AI-related technologies after the US midterm elections had driven selling across the US market, particularly in technology stocks. It said investors were especially concerned that tougher rules on data centre construction could slow projects.