NEW YORK CITY, New York: A wave of selling hit artificial intelligence-related stocks around the world on September 14 as warnings from some of the industry's leading executives about the risks of rapid AI development rattled investors.

The declines come as companies increasingly rely on debt and circular financing to support ambitious AI spending plans, while global borrowing costs remain elevated amid multi-year-high bond yields.

Anthropic CEO Dario Amodei called on AI companies over the weekend to slow the pace at which they advance model capabilities due to concerns about the potential misuse of artificial intelligence. Elon Musk, who runs xAI, and OpenAI CEO Sam Altman said they agreed with Amodei.

Altman also said OpenAI would not proceed with an initial public offering this year, citing safety concerns.

The Nasdaq 100 fell 1.2 percent to a six-week low in early trading, with semiconductor stocks among the biggest losers.

"If this does lead to sort of a slowdown and a rethink of AI spending, that will have ramifications for the economy and some important sectors of the stock market, because essentially, we've been running hot based on AI spending," said Steve Sosnick, chief market analyst at Interactive Brokers.

The Philadelphia chip index dropped 5.1 percent. Nvidia fell 3.6 percent, Advanced Micro Devices declined 5.6 percent, and Micron lost six percent, while Musk's SpaceX shed 1.6 percent.

Semiconductor equipment makers Lam Research and Applied Materials each fell six percent. Bloom Energy dropped 6.8 percent, and GE Vernova declined 7.4 percent.

The selloff spread overseas. Europe's technology sector fell 2.2 percent, with ASML down 5.9 percent and Infineon and Siemens Energy also recording steep losses. In Asia, SoftBank plunged as much as 13.2 percent, while TSMC and SK Hynix retreated.

Concerns over potential AI harm intensified earlier this month when Anthropic researcher Jacob Coxon resigned, saying the "people building AI earnestly believe that it could kill us all by the end of the decade."

Days later, Anthropic released a threat intelligence report detailing how its Claude AI models had been used for activities ranging from weapons development and cyber operations to surveillance and fraud.

Over the weekend, Amodei wrote that within six to 12 months, AI agents "could be capable of taking over the entire internet potentially causing hundreds of billions of dollars in damage." Separately, Altman described risks of human extinction posed by AI as "unacceptable".

Several U.S. lawmakers have raised concerns about rapid AI advances and called for new rules. President Donald Trump, however, said a "sick conspiracy" against AI and data centers exists, appearing to play down concerns expressed by industry leaders.

AI-related investments have driven much of the rise in global equities since OpenAI launched ChatGPT in 2022. More recently, cyberattacks by rogue AI agents and public discontent over data center construction have increased opposition to the industry's development.

The United States and China are expected to hold AI safety talks as part of bilateral discussions this month. China's state-backed Global Times criticized Amodei's essay as a "Cold War playbook" intended to restrict China's technological development.

OpenAI and Anthropic are also facing growing competition from cheaper Chinese models, including Moonshot AI's Kimi K3, Alibaba's Qwen and DeepSeek's offerings.

Not all investors accepted the warnings. Michael Burry, known for his bets against the U.S. housing market before the 2008 financial crisis, called them "hype and puffery" and "cover for real uncontrollable slowing growth".

Morgan Stanley CEO Ted Pick has forecast AI spending will exceed US$1.3 trillion by 2027.

"The key question is whether this is the first sign that the extraordinary AI investment cycle might eventually moderate. For now, that seems unlikely. The competitive race between companies and countries remains intense, and it's difficult to imagine firms voluntarily stepping back while rivals continue to push ahead," Deutsche Bank said.

Anthropic is continuing preparations for a public debut expected next month, while Japanese chipmaker Kioxia Holdings is considering raising at least $10 billion through a U.S. listing of American depositary receipts, according to a report.