Image source, Bloomberg via Getty Images By Rachel Clun , Reporting from New York and Osmond Chia , Reporting from Singapore Published 5 November 2026 Updated 1 hour ago Trillions of dollars has been wiped off the stock value of major tech firms in the US, Europe and Asia in a market rout after the US midterm elections sparked concerns of a slowdown in artificial intelligence (AI) development.
Shares in firms across the tech sector plummeted following Democratic wins after election campaigns run on slowing AI.
The tech-heavy Nasdaq composite index closed down by more than 5.5% on Thursday, losing an estimated $2.5tn (£1.9tn) in market value, according to Dow Jones data, while other key US stock indexes also saw big losses in their worst days since 2025.
The sell-off comes on top of broader concerns about whether the huge amounts being spent on AI will pay off.
In Asia, tech-heavy indexes fell sharply on Friday morning as firms that make the computer chips and other equipment that power AI saw their shares slide.
The Nikkei 225 in Japan was 6.3% lower in the afternoon as shares in memory chip maker Kioxia lost almost 11.5% and rival Tokyo Electron slipped by 5.8%.
South Korean chipmaker SK Hynix fell by more than 8.8%, while Samsung was down by around 6%.
The sell-off in Seoul sent the Kospi index plunging more than 8% in morning trading, triggering a so-called circuit breaker, a mechanism that temporarily halts trading to curb panic selling. The Kospi was around 5% lower in the afternoon.
The Taiwan stock market suffered its biggest weekly decline since 2001, according to LSEG data, with the Taiex falling by 4.5% on Friday.
It marks a "continuation of worries" over the level of spending on AI infrastructure, said MarketWatch chips analyst Britney Nguyen.
Democrats in races across the US campaigned to slow the growth of data centres and AI, and there were dozens of measures on ballots around the country aimed at restricting the development of the hubs crucial for powering the technology.
They won both the US Senate and House of Representatives in Tuesday's midterms, taking control of Congress for the rest of President Donald Trump's presidency.
Texas' Democratic governor-elect Gina Hinojosa campaigned heavily against data centres, pledging a moratorium on new construction in the sector.
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In a social media post, Trump blamed the slide on his political opponents.
"The Stock Market suffered one of the Worst Days in History based on the results of the Election," he said.
"Remember, it wasn't Republicans, it was Dumocrats. Do not fear, however, we will soon, one way or the other, be BIGGER AND STRONGER THAN EVER BEFORE. MAKE AMERICA GREAT AGAIN!"
Later on Thursday night he appeared to take aim at voters too.
"The Stock Market crashed today because the Dumocrats had a big Tuesday — So sad to see, you only have yourselves to blame!" he wrote on Truth Social.
Some Democrats have argued that AI has grown too big without any safeguards or oversight and have promised, with their new power in Congress, to change that.
"Americans don't want Big Tech oligarchs wrecking the environment, gutting jobs and threatening humanity's future. NATIONAL DATA CENTER MORATORIUM NOW," Dem…