Building anxiety that this year's record rally linked to all things artificial intelligence has made some traders question whether the billions spent on the industry might not see the big returns as soon as hoped.

Compounding the downbeat mood are concerns that the Federal Reserve will decide against a third-straight interest rate cut next month, as stubborn inflation plays up against a weakening jobs market.

The rally this year has been driven by the fears of missing out on the AI bandwagon and bets on US borrowing costs coming down.

That has put two major releases this week well in the spotlight.

Wednesday sees Nvidia -- at the forefront of the AI push with its top-end chips -- release its latest earnings report, which will be pored over for an idea about the outlook for the sector.

Earnings from retailers Home Depot, Target and Walmart will meanwhile give an insight into consumer sentiment.

Investors have become sensitive to any negative news surrounding the AI universe, and were given a jolt this week when it emerged that tech billionaire Peter Thiel's hedge fund had offloaded all its Nvidia stake, which Bloomberg valued at about $100 million.

Neil Wilson at Saxo Markets said in a note: "Analysts are sounding upbeat ahead of the report. But the bar is set very high and we know that if investors are starting to wobble the whole house of cards can come crashing down at any point.

"Profitability at the stocks at the heart of the AI bubble remains very strong, but any weakness evident in the (third quarter) from Nvidia would be punished hard by markets."

Thursday is expected to see the release of the US September jobs report after delays due to the government shutdown. The data will provide a fresh snapshot of the world's number one economy and give an idea about the chances of another rate cut.

The chances of a December reduction are around 50-50, with Fed officials recently flagging concerns about inflation more than the jobs market.

Bank boss Jerome Powell said last month that another cut at its December policy meeting was not a "foregone conclusion", a comment that has been echoed by a number of colleagues.

Still, Fed governor Christopher Waller said Monday that "my focus is on the labour market, and after months of weakening, it is unlikely that the September jobs report later this week or any other data that's going to come out in the next few weeks is going to change my view that another cut is in order".

Meanwhile, Fed vice chair Philip Jefferson said that while he saw further downside risks to jobs, he wanted decision makers to proceed carefully, suggesting he is keeping his powder dry.

After a day deep in the red on Wall Street, Asia also struggled.

Tokyo, Sydney, Seoul and Taipei all shed more than one percent, while there were also big losses in Hong Kong, Shanghai, Singapore and Wellington.

Bitcoin continued to struggle with the risk-averse atmosphere on markets, and was sitting at around $91,300, having wiped out all its gains for the year. The crypto coin has lost more than a quarter of its value since hitting a record high of $126,251 last month.

- Key figures at around 0230 GMT -

Tokyo - Nikkei 225: DOWN 1.8 percent at 49,432.56 (break)

Hong Kong - Hang Seng Index: DOWN 0.9 percent at 26,128.79

Shanghai - Composite: DOWN 0.4 percent at 3,957.29

Dollar/yen: UP at 155.25 yen from 155.23 yen on Monday

Euro/dollar: UP at $1.1591 from $1.1589

Pound/dollar: DOWN at $1.3152 from $1.3156

Euro/pound: UP at 88.13 pence from 88.09 pence

West Texas Intermediate: DOWN 0.5 percent at $59.64 per barrel

Brent North Sea Crude: DOWN 0.4 percent at $63.92 per barrel

New York - Dow: DOWN 1.2 percent at 46,590.24 points (close)

London - FTSE 100: DOWN 0.2 percent at 9,675.43 points (close)

dan/lb

NVIDIA

TARGET

Walmart

INDEX CORP.

Dow