Global Tech Sell-Off Deepens as AI Debt Fears and Inflation Data Trigger Market Rout

Key points

• The Nasdaq Composite fell 1.2% and the S&P 500 dropped 0.4% in early US trading, extending a sharp sell-off that began Wednesday after hotter-than-expected US wholesale inflation data.
• Asian markets led the decline, with South Korea’s Kospi index plunging 7.6% to a six-month low, triggering a circuit breaker. Chipmakers SK Hynix and Samsung Electronics fell over 10% and 9.5%, respectively.
• CoreWeave, a key AI data center provider, fell 7% on Thursday after dropping 15.5% the previous day. Its shares are down 66% from their post-IPO peak, reflecting fears that high debt levels are unsustainable in a rising rate environment.
• TSMC shares fell 2% despite strong earnings, as CEO C.C. Wei cited rising component prices and macroeconomic uncertainty. The broader semiconductor index is down 23% since its June peak.
• The Dow Jones Industrial Average rose 0.68%, showing a divergence from tech-heavy indices, as investors rotated into defensive sectors and Treasury bonds rallied, pushing yields lower.

Background

This sell-off follows a series of recent market corrections. On October 15, 2026, the Nasdaq had already fallen 1.88% the previous day due to hot CPI data, with the VIX volatility index jumping to 16.87. Earlier in October, AI revenue concerns and Federal Reserve rate hike signals had caused the S&P 500 and Nasdaq to fall, while the Dow remained resilient. In late September, chipmakers had cooled after a rally, and geopolitical tensions with Iran had dominated sentiment, though oil prices had since eased.

How outlets are covering it

CNN emphasizes the structural risks in the AI sector, highlighting that 'neocloud' providers like CoreWeave are heavily indebted and that a Gartner report predicts over 80% of such firms will cease operations by 2030. It also notes competitive pressure from Chinese chipmaker CXMT. CNBC focuses on the immediate market mechanics, detailing the circuit breaker in South Korea and the specific earnings beats that failed to save chipmakers, while also noting Ericsson’s strong performance as a counter-trend. Yahoo Finance provides the raw data, showing the S&P 500 at 7,699.98 and the Nasdaq at 26,467.44, confirming the broad market weakness despite some defensive gains in consumer staples and utilities.

Why it matters

The sell-off signals a potential shift in market sentiment from AI optimism to caution regarding valuation and debt. If the Federal Reserve raises rates due to persistent inflation, the cost of capital for AI infrastructure will rise, potentially stalling the buildout. This could impact broader economic growth, as AI investment is now a significant portion of US GDP. The divergence between the Dow and Nasdaq suggests a rotation into value and defensive stocks, which may persist if inflation remains sticky.

What to watch

Investors will watch for further signs of AI demand, particularly from private companies like Anthropic and OpenAI, and any updates on Federal Reserve policy. The performance of semiconductor stocks and neocloud providers will be key indicators of whether the sell-off is a correction or a deeper trend. Additionally, the impact of Chinese competition on US and South Korean chipmakers will be closely monitored.