Some $2.3 billion in market value was wiped off the tech-focused Nasdaq 100, which dropped 6.3% Thursday. Another $2.8 trillion was erased from the S&P 500’s market value as it fell 4.4% — the worst day for both indexes in 18 months, when President Donald Trump’s global tariffs rocked markets.

U.S. futures were mixed early Friday, but European shares also opened lower after the dramatic sell-off continued in Asia.

South Korea’s Kospi index tumbled more than 8%, triggering a temporary market-wide trading halt. There, AI data center memory suppliers Samsung and SK Hynix plunged more than 10% in the early hours, before recovering some of their losses. Japan’s Nikkei 225 index fell as much as 6%, entering bear-market territory.

In Taiwan, home to some of the most critical AI companies, including chip supplier TSMC, the benchmark TAIEX index dropped 9%.

The picture was little better in Europe. London’s FTSE 100 index fell by nearly 2%, while the French and German indexes, CAC40 and DAX, took similar hits.

“Markets are being punished according to their dependence on the U.S. AI infrastructure cycle,” Charu Chanana, chief investment strategist at Singapore-based SAXO Markets, told NBC News in emailed comments.

The companies in Taiwan, South Korea and Japan are “clearly highly linked to the global AI capex cycle and hence I am not surprised to see the magnitude of correction today following the sharp correction in the U.S.,” Tai Hui, J.P. Morgan’s APAC chief market strategist, told NBC News in emailed comments.

The plunge came after the stunning midterm results that will see a crop of anti-AI and data center opponent politicians take office, including Gov.-elect Gina Hinojosa in Texas, the largest data center market in the country.

Gina Hinojosa as she was announced the next governor of Texas at her watch party in Austin on Tuesday. Mikala Compton / The Austin American-Statesman via Getty

The Democratic Congress could tighten scrutiny of the industry, including AI infrastructure projects, which could cause delays and additional costs, adding to worries investors have about the profitability of these investments.

Asian markets were already in trouble

The months leading up to the American elections had already been a rollercoaster for Asian investors, who saw their fortunes soar in June during the AI stock boom, but have been suffering from a brutal recent sell-off.

A sense that initial valuations of key AI companies were inflated was troublesome enough for markets in Asia, but the Democratic sweep has introduced another layer of uncertainty.

Markets had largely expected losses for Trump’s Republicans, but not on this scale.

“This matters enormously for Asia because much of the hardware supporting America’s AI ambitions is manufactured here,” Chanana, from SAXO Markets, said.