White House science advisor David Sacks called on Thursday for Anthropic's initial public offering to be paused until claims by a former researcher about existential AI risks can be fully investigated.

Sacks, chairman of the President’s Council of Advisors on Science and Technology, posted on X that Anthropic’s IPO “should certainly be paused until the claims made by the whistleblower have been investigated.” The statement followed the resignation of Jacob Coxon, a pre-training researcher at Anthropic who previously worked at OpenAI.

Coxon announced his departure on Tuesday and warned that both companies are “racing straight to self-improving superintelligence and gambling with our lives.” He stated that researchers building the technology “earnestly believe that it could kill us all by the end of the decade.” Current Anthropic Alignment Science lead Evan Hubinger publicly agreed with the assessment, writing that he believes the probability exceeds 10 percent within the next decade.

Anthropic has confidentially filed paperwork for what could become one of the largest IPOs in history. The company’s private valuation reached $965 billion after a $65 billion funding round earlier this year, with market speculation pointing to a potential public valuation near $2 trillion. The firm filed its S-1 with the SEC in June.

Sacks has previously criticized well-funded campaigns promoting AI doom scenarios. His latest intervention highlights growing scrutiny of AI governance as frontier labs accelerate development. Lawmakers from both parties have signaled interest in stronger safeguards amid the debate.

Anthropic has positioned itself as a safety-focused lab, though critics argue its rapid push toward more capable models undercut those claims. The company has not publicly responded to Sacks’ call for a pause.