US futures also declined, while oil prices fell.

Tokyo's Nikkei 225 index shed 5 per cent to 68,783.50, and the Kospi in Seoul plunged 8.4 per cent to 8,182.54.

Hong Kong's Hang Seng lost 1.9 per cent to 22,644.49, while the Shanghai Composite index slipped 2.1 per cent to 4,032.30.

In Australia, the S&P/ASX 200 was nearly unchanged at 8,745.80.

Taiwan's Taiex gave up 3.3 per cent.

Both the Nikkei and Kospi hit record highs earlier this week.

The wide swings are typical of recent volatility in markets as investors react to the deluge of dollars heading into AI data centres and other investments.

On Thursday, the US stock market drifted to a mixed finish after several AI stocks veered back up the roller coaster, while Apple shares dropped 6.1 per cent after the company hiked prices on many of its products.

The S&P 500 finished nearly unchanged with a dip of less than 0.1 per cent after swinging between gains and losses throughout the day. The Dow Jones Industrial Average added 71 points, or 0.1 per cent, and the Nasdaq composite fell 0.5 per cent.

Micron Technology helped lead the market after jumping 15.7 per cent. The maker of computer memory reported much bigger profit and revenue for the latest quarter than analysts expected, and it gave a stronger growth forecast for the current quarter than Wall Street expected. That helped allay worries a bit that its stock had grown too expensive after coming into the day with a surge of 267 per cent so far this year.

Micron and AI stocks broadly have been under intermittent pressure recently because of worries that their profits can't possibly keep pace with the tremendous rallies in their stock prices. Beyond Micron, Qualcomm said late Wednesday that the acceleration of the AI era is forcing it to upgrade forecasts for its own growth in upcoming years.