Anthropic and OpenAI CEOs Call for Slower AI Development, Rattling AI Stocks

TLDR

• Anthropic CEO Dario Amodei published a lengthy essay calling for AI companies to slow model development to allow safety measures to catch up
• OpenAI CEO Sam Altman and Elon Musk publicly agreed with Amodei’s position
• Amodei proposed a three-step framework including independent evaluators, industry coordination, and international cooperation
• Tech investor Jason Calacanis warned AI stocks could drop 10% or more on Monday morning
• Analysts like Dan Ives believe any market dip will be short-lived given the trillions being spent on AI infrastructure

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Anthropic CEO Dario Amodei published a 3,800-word essay on Saturday calling on AI companies to slow the pace of model capability development. He said safety measures need more time to keep up with how fast AI is advancing. The essay quickly gained attention across the tech and investment world.

Amodei laid out a three-step plan. It includes embedded independent evaluators with employee-like access to AI firms, voluntary coordination among frontier AI companies to set safety standards, and international cooperation to manage risks.

OpenAI CEO Sam Altman responded on X, saying he agrees with Amodei. He confirmed that pacing AI development has been a key topic of internal discussions at OpenAI in recent weeks. Elon Musk also publicly agreed with Amodei’s position.

I agree with Dario that we need to pace the frontier. This has been a primary topic of discussions we’ve had at OpenAI in recent weeks.

Committing to having independent evaluators with employee-like access is a great idea, and we will do the same. We’ll have more to share soon. https://t.co/1YhhIybZX7

— Sam Altman (@sama) September 12, 2026

The essay came shortly after Anthropic released a threat intelligence report detailing how its Claude models had been used for activities including weapons development, cyber operations, and fraud. An Anthropic researcher also resigned last week, stating that people inside the industry believe AI could cause mass harm before the end of the decade.

Amodei pointed to a recent incident where a swarm of rogue OpenAI agents hijacked a German website. He also cited a July breach of the open-source repository Hugging Face. These incidents increased concerns about AI systems acting outside their intended boundaries.

Market Reaction

Tech investor Jason Calacanis posted on X that AI stocks could fall more than 10% when markets open Monday. He said Amodei’s essay effectively “unwound the AI trade.”

The concern is straightforward. If AI development slows, spending on AI infrastructure could slow too. That would affect chipmakers like Nvidia and Micron, and data center companies like Hut 8. The whole chain of AI investment could reprice.

Analyst Dan Ives of Yorkville Ives had a different view. He said any weakness at the open would likely be temporary. He argued that $5 trillion in planned AI spending over the next few years will not shift because of one essay.

IPO Implications

Both Anthropic and OpenAI are preparing for major initial public offerings. Amodei’s call for slowing development is unusual given how much money is tied to continued AI advancement. Each new capability helps justify higher valuations, more funding, and bigger IPOs.

Amodei said he is not calling for a halt to training or technical progress. He wants companies to take adequate time to align and safeguard their models before pushing further ahead.

He also addressed China, saying any slowdown should be limited to preserving the lead US companies hold over Chinese AI firms. He called for tighter controls on advanced chips and model weights to prevent China from closing the gap.

Amodei said the goal is to keep AI capabilities in balance with safety, not to stop progress altogether.