The selling followed a downbeat session on Wall Street after US jobs data clouded hopes of further interest rate cuts and fears about whether red-hot valuations for artificial intelligence shares are justified.

Seoul's benchmark Kospi index was trading down nearly four percent, while Tokyo's Nikkei index shed 2.3 percent in morning trade.

Samsung Electronics sank 4.8 percent and rival SK hynix plunged more than nine percent. The firms are two of the world's leading memory chip makers.

The downturn comes a day after a region-wide rally fuelled by an earnings report from AI bellwether Nvidia, which topped expectations on fierce demand for advanced chips.

Chief executive Jensen Huang brushed off fears of an artificial intelligence bubble.

Nvidia, whose chips are used to train and power generative AI systems, last month became the world's first company valued above $5 trillion, though its market cap has since receded to around $4.4 trillion.

Multibillion-dollar investment into AI has been a key driver of the global surge in mostly technology equities, sending valuations to record highs.

"For now, movements in the domestic (South Korean) market are inevitably tied to day swings in US tech stocks, including Nasdaq futures and Nvidia's after-hours trading," said Han Ji-young, an analyst from Kiwoom Securities.

"Nvidia's earnings were undeniably a surprise, but in a time of heightened short-term volatility, even strong catalysts struggle to generate meaningful upside," he added.

AI-related spending is expected to reach approximately $1.5 trillion by 2025, according to US research firm Gartner, and more than $2 trillion in 2026 -- amounting to nearly two percent of global gross domestic product.

Geopolitical tensions are helping drive the frenzy, primarily to build data centres housing tens of thousands of expensive chips that require phenomenal electrical power and energy-hungry cooling.

Japan's SoftBank Group, a major backer of ChatGPT maker OpenAI, tumbled as much as 10.7 percent in early trade.

SoftBank, OpenAI and cloud giant Oracle are jointly leading the $500 billion Stargate project to build AI infrastructure in the United States announced by President Donald Trump in January.

SPI Asset Management's Stephen Innes said there was no "single catalyst" for the stock routs.

"What we saw was the market hitting a psychological air pocket -- the kind of reversal every veteran trader has lived through, yet cannot reasonably quantify or make sense of in real time," he said.

"Japan, Korea, Australia all opened on the defensive, with traders fully aware that the Nvidia-led optimism evaporated before the US lunch hour."