What sparked the latest AI stock sell-off in the US and Asia

AI-related chip stocks fell sharply across the US and Asia as investors grew concerned about heavy spending on artificial intelligence and rising competition in the sector.

The sell-off spread from Wall Street to Asian markets after Nvidia shares dropped 5% on Monday, allowing Apple to reclaim its position as the world's most valuable publicly listed company.

South Korean chipmakers lead losses

South Korea's benchmark Kospi index plunged as much as 8% on Tuesday morning, triggering a temporary trading halt under the market's circuit breaker system. The index later closed 10.8% lower.

Technology companies led the decline, with Samsung Electronics and SK Hynix each falling more than 13%.

In the US, shares of SK Hynix also dropped 7.5%, trading well below the company's Nasdaq debut price earlier this month.

Japan's Nikkei 225 also ended the day nearly 4% lower.

AI spending concerns weigh on investors

Nvidia's decline followed a Wall Street Journal report that the company is in talks to invest about $250 billion in OpenAI as part of a major data-centre project.

The report added to investor concerns over the scale of AI-related spending and intensifying competition, particularly from Chinese companies.

Jun Bei Liu, founder of investment firm Ten Cap, told the BBC that investors are taking profits after the sector's strong rally but may return to AI stocks after the US holiday season.

Chinese chipmaker surges after market debut

While many technology stocks declined, China's ChangXin Memory Technologies (CXMT) surged nearly 470% during its Shanghai stock market debut.

The company said it plans to use most of the proceeds from its initial public offering to expand production capacity and invest in research and development.

CXMT manufactures dynamic random-access memory (DRAM) chips used in AI data centres, smartphones, personal computers, tablets and other electronic devices.