Security

Anthropic's AI Brake Divides Tech Industry: Nasdaq Down 1.5 Percent

3 min read

TL;DR Too Long; Didn’t read

Nasdaq-100 futures fell by 1.5 percent on Monday after Microsoft CEO Satya Nadella and US President Donald Trump took opposing positions on Dario Amodei's call for an AI speed limit. Nadella announced a code of conduct for Microsoft's own AI models, while Trump rejected government intervention, citing the race with China. OpenAI CEO Sam Altman confirmed in a Fortune interview that training runs would be paused if necessary.

An oversized red brake disc blocks a glowing server track racing upward, while a stock chart arrow abruptly breaks downward in the background. Image generated with GPT Image 2

Key takeaways

  • Nadella calls an AI without human control not worth pursuing in a post on X and announces a code of conduct.
  • Altman tells Fortune that OpenAI will pause training runs if no safety evidence for controllability is achieved.
  • Trump opposes a regulatory AI brake and points to the race with China.
  • Nasdaq-100 futures fell by 1.5 percent on Monday, Nvidia shares dropped three percent.
  • Chip stocks like Arm and Marvell as well as cloud provider CoreWeave each lost six percent on the stock market.
  • Microsoft's code of conduct for its proprietary MAI models enters public consultation starting today.

One day after Dario Amodei’s call for an AI speed limit, the tech industry is split: Microsoft CEO Satya Nadella welcomes a deliberate slowdown on the platform X and announces a code of conduct for the company’s own AI models. US President Donald Trump rejects government intervention and points to the race with China. On Wall Street, Nasdaq-100 futures fell 1.5 percent on Monday.

Altman backs pacing pledge with a safety caveat

In the interview with Fortune editor-in-chief Alyson Shontell published on Sunday, OpenAI CEO Sam Altman elaborated on the agreement with Amodei’s essay he had voiced on X the day before. Asked whether it is possible to build an AI system no longer under human control, Altman replied it was “of course” possible – but added that it is not a goal his company should pursue. OpenAI will pause training runs more often going forward to fit in extra safety and alignment work before the next capability jump, he announced.

According to Altman, a safety case is central: OpenAI does not want to train any model for which it cannot make a solid claim about controllability and alignment. He also hinted at coordination with industry peers to jointly slow the pace of development while safety work keeps up with growing model capabilities. If necessary, he said, he would stand up to his own investors over it. In a late-night X post the night before, he had already said his company stands uncompromisingly on the side of humanity and would not accept a future without human control over AI systems. His comments add concrete detail on OpenAI’s own approach to Amodei’s essay from the previous day.

Nadella announces code of conduct for Microsoft’s AI models

Microsoft CEO Satya Nadella responded on Sunday on X with his own position: any pursuit of superintelligence has to rest on the principle that an AI not helping humanity and not under human control is not worth pursuing, he wrote. Microsoft welcomes the “deliberate pacing” needed to make alignment the actual design goal, along with proposals such as embedded external evaluators inside the labs. Nadella had already warned in July about hidden costs of commercial AI use.

Specifically, Nadella announced that starting Monday, a code of conduct for Microsoft’s in-house MAI model family would be published for public consultation. The code is meant to provide documented behavioral standards for the first time for the MAI models launched in June 2026 under AI chief Mustafa Suleyman, spanning areas from language processing to coding to image and voice generation. Control over advanced AI should not rest with a handful of companies, Nadella argued, but needs broad participation from academia, governments and industry. Neither Google nor Meta have publicly commented on Nadella’s move so far.

Trump rejects the brake, investors turn jittery

US President Donald Trump rejected the AI leaders’ demand on Sunday during his stay in Ireland. Speaking to reporters, he said guardrails can certainly be put in place, but there are also negative forces behind the warnings conjuring up things that will not happen at all. The US leads China in AI, “and I want to keep it that way, because whoever wins with AI wins.” House Speaker Mike Johnson backed that line on CNN the day before and warned against a congressional moratorium, arguing China would otherwise overtake the US. The administration had previously considered setting up its own AI oversight agency modeled on Finra.

The dispute rattled financial markets: Nasdaq-100 futures fell 1.5 percent on Monday, the S&P 500 dropped 0.8 percent. Nvidia stock lost roughly three percent, according to NBC News, while chip stocks Arm and Marvell and cloud provider CoreWeave each fell about six percent. Just the week before, Nvidia’s stock had recovered significantly.

Whether Amodei’s call for government-mediated, joint safety standards finds any traction at all given the White House’s clear rejection remains an open question. Microsoft’s public consultation on its own code of conduct, starting today, offers a first test of whether voluntary commitments from individual companies can hold without government coordination.

Frequently asked questions

Which companies have commented on AI pacing so far?

Anthropic, OpenAI, and Tesla founder Elon Musk positioned themselves on September 12 and 13, and now Microsoft joins in through Nadella. Google and Meta have not yet commented publicly.

What exactly does Microsoft's new code of conduct regulate?

It establishes documented behavioral standards for the proprietary MAI model family for the first time, covering everything from language processing to image generation, and enters public consultation starting September 14.

How strongly did financial markets react specifically?

Nasdaq-100 futures fell 1.5 percent, the S&P 500 dropped 0.8 percent. Nvidia lost about three percent, Arm, Marvell, and CoreWeave each about six percent.

What position does the US government take on the requested slowdown?

Trump opposes regulatory intervention and points to competition with China. House Speaker Mike Johnson backed this line and warned against a congressional moratorium.

What does Anthropic plan as the next step in the debate?

Amodei's essay calls for government-mediated, joint safety standards among leading AI companies. The essay does not yet name a timeline for negotiating them.

Sources (4)
  1. Satya Nadella on X: statement on superintelligence and pacing
  2. Fortune: exclusive interview with Sam Altman (Alyson Shontell)
  3. Al Jazeera: Trump dismisses calls for AI slowdown from leading tech CEOs
  4. NBC News: Stocks tumble after AI leaders warn that the industry should slow down

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