Asian Markets Tumble as AI Sector Selloff Drags Tokyo Nikkei Down Nearly 5%

TOKYO — Asian stock markets plunged on Thursday, with Japan's benchmark Nikkei 225 falling nearly 5% in a broad-based rout driven by heavy selling of artificial intelligence stocks. The sharp decline sent shockwaves across the region as investors grew increasingly concerned that valuations for chipmakers and technology firms have become unsustainable.

The sell-off was led by computer hardware manufacturers, with shares of major semiconductor companies dropping significantly on worries regarding future demand for memory chips and processors. Traders expressed skepticism about whether current growth rates in AI infrastructure spending could be maintained over the long term, prompting a rapid reassessment of asset prices that had surged throughout 2025.

In Tokyo, the Nikkei 225 erased months of gains as technology stocks dragged down the broader index. The decline was not isolated to Japan; markets in South Korea and Taiwan also suffered steep losses. Both economies are heavily reliant on semiconductor exports, making them particularly vulnerable to a correction in the AI supply chain. In Seoul, the Kospi index fell sharply alongside its Japanese counterpart, while Taipei's weighted index saw significant volatility as local chip giants faced intense selling pressure.

Analysts noted that the market reaction reflected a growing fear of an overheated sector. Prices for key technology stocks had risen to levels where even minor doubts about earnings sustainability triggered aggressive profit-taking. The concern centers on whether global demand for high-performance computing components can justify current price-to-earnings ratios, or if companies have priced in growth scenarios that may not materialize.

The volatility extended beyond pure-play chipmakers to include broader technology indices and industrial stocks tied to the AI supply chain. Investors moved quickly to reduce exposure, fearing a prolonged correction could ripple through other sectors dependent on digital transformation spending.

Market participants are now watching for further signals from corporate earnings reports and guidance updates later this week. The immediate question remains whether the current selloff represents a healthy recalibration of valuations or the beginning of a deeper downturn in the technology sector. As trading continues, uncertainty persists regarding when investor confidence might stabilize and if demand fundamentals can support the high prices seen earlier in the year.

The situation is expected to influence market sentiment heading into European and U.S. trading sessions later Thursday, with global investors bracing for potential contagion from Asia's tech-heavy decline.