The Tokyo and Seoul stock markets plunge after the collapse of American technology stocks

The Tokyo and Seoul stock markets plunged on Friday in the wake of the fall on Wall Street, amid concerns after the results of the American elections which could slow down investments in data centers dedicated to artificial intelligence (AI).

The Nikkei, Tokyo's flagship index, fell by 5.69% to 57,602 points around 00:50 GMT (02:50 in Paris) while in South Korea, the Kospi index fell by 7.92% to 4,957 points, triggering an automatic trading suspension mechanism which interrupted transactions for twenty minutes.

Investors initially applauded the rout inflicted by the Democrats during the American mid-term elections on Tuesday on the Republican Party of President Donald Trump. But they have since adopted a more cautious stance, fearing that the electoral upheaval could penalize key investments in AI, seen as essential to economic growth.

Among the major American indices, the one that suffered the most was the Nasdaq, oriented towards technology stocks, which ended down 5.52% on Thursday during a massive selling session that heavily hit Nvidia and other stocks in the semiconductor sector. This is the Nasdaq's worst decline since April 2025.

In South Korea on Friday, makers of memory chips (whose cutting-edge components are used with other semiconductors specialized in data processing to run AI tools) were also affected. Samsung Electronics fell almost 10%, while SK hynix lost more than 11%. The tech debacle also affected semiconductor-related stocks in Japan, with Tokyo Electron shares falling around 9% and Kioxia dropping 13%.

“Following the Democrats' victory in the midterm elections, concerns about tougher regulations on AI-related technologies caused massive selling across the US market, particularly in technology stocks, leading to declines in the three main US indices,” said online broker Monex.

“In particular, some fear that stricter regulations around data center construction could slow down construction projects,” he adds.

Around the world, governments and tech giants are in a mad race to build data centers to train and operate AI models - part of a global boom worth hundreds of billions of dollars.