Chip stocks crash worldwide: Seoul halts trading, Nasdaq 100 has worst day since 2020

Red screens everywhere: a wave of selling in chip and tech stocks has rolled from Wall Street through Asia to Frankfurt. In Seoul, trading had to be paused for a while.

What happened?

It started in the US. Big tech and chip companies lost billions in market value within hours. The Nasdaq 100, the index of the biggest tech-heavy US companies, dropped 6.4%. That is its worst daily loss since the Covid crash of March 2020.

The broader S&P 500 had its worst day since April 2025.

Asia felt it next. South Korea's Kospi fell by almost 9% in early trading and still closed more than 6% lower. Japan's Nikkei 225 sank 6%.

In Seoul, an automatic circuit breaker (a built-in pause button for panic selling) stopped trading for 20 minutes. The government called an emergency meeting with financial regulators and the central bank.

Why is everyone talking about it?

Investors are getting nervous about whether the huge spending on artificial intelligence and new data centres will ever pay off. Memory and high-performance chip makers are under particular pressure.

Then came politics. After the Democrats' win in the US midterms (the congressional elections halfway through a presidential term), markets fear more debate over AI regulation and where data centres can be built.

Stephan Kemper, chief investment strategist at BNP Paribas, describes the worry as a simple chain: if permits for power and buildings stall, finished data-centre shells will be missing from 2028, and high-performance chips bought on credit today could not earn any money. He calls it a "black swan" event, a shock out of nowhere, and says it is important not to panic. "Such painful clean-ups are part of the stock market," he says.

Wait, what about Germany?

The DAX, Germany's leading index, had been at record highs. It slipped by up to 2% at the open and fell back below 26,000 points. That is mild compared with the US and Asia, because few big tech names sit in the DAX.

What's next?

The AI company Anthropic had planned to go public in the coming weeks. According to Reuters, citing insiders, its roadshow for investors next week, ahead of a November listing, is now in doubt.

Earlier today, trading was already halted in Seoul as the sell-off hit Asia. What comes next depends on whether the selling continues when the markets reopen.