AI stock sell-off hits Asia as Kospi falls 8% and Nikkei drops 4.9%

A sell-off in shares tied to artificial intelligence spread across global markets on 15 October 2026. South Korea's Kospi 200, an index weighted heavily towards memory chip makers, closed down 8.1% at a six-month low. The slide was severe enough to trip circuit breakers that paused trading several times during the session.

Among the heaviest losers, SK Hynix sank close to 11% and Samsung Electronics lost 9.5%. In Tokyo, the Nikkei 225 fell 4.9%, dragged down by an 11% plunge in memory chip producer Kioxia and a 10% decline in SoftBank, a major backer of ChatGPT maker OpenAI.

Inflation data sparks the rout

The Asian losses followed a weak session on Wall Street on 14 October, when the Nasdaq Composite lost 1.9% and the S&P 500 shed 1.1%, its worst day since July. The trigger was US data showing consumer prices rose 3.7% in September, above forecasts and the quickest pace since the CPI reached a three-year high of 4.2% in May.

The reading has led investors to anticipate further rate rises from the Federal Reserve, with some traders betting on a move as early as the end of October. Deutsche Bank analyst Jim Reid stressed that fuel costs, lifted by fallout from the US war on Iran, were not the only driver. "This wasn't just an energy surge driving prices higher," he said, pointing to increases across the consumer basket.

IMF warning and wider markets

The rout came shortly after the International Monetary Fund warned that a crash in AI share prices could threaten global financial stability. The IMF said the fallout of such a correction could be worldwide, with Asian markets most exposed after the US, while the UK and eurozone might be somewhat shielded, though investors holding US assets would still suffer.

In China, Shanghai's CSI 300 fell as much as 2.4% to its lowest level since August 2025. Taiwan's TSMC, Asia's most valuable company, slipped 2% even after posting a sixth consecutive quarterly profit. European markets opened lower, with the Stoxx 600 down 0.4% and Germany's DAX off 0.53%, while Nasdaq 100 futures pointed to a 1% drop in the US.

The swings show how exposed the AI investment boom has become to heavy borrowing and the prospect of tighter monetary policy. Asian suppliers of the memory and chips that power AI infrastructure have so far absorbed the sharpest losses.