An artificial intelligence researcher who spent three years on pre-training at OpenAI and Anthropic resigned this week and said he is leaving the industry entirely.

Jacob Coxon, 27, posted on X that neither company is acting responsibly. "They are racing straight to self-improving superintelligence and gambling with our lives," he wrote.

Coxon joined OpenAI as a member of technical staff in 2023 and contributed to work on GPT-4o before moving to Anthropic earlier in 2026. He said the competitive push at both firms ignores the civilizational stakes involved.

"The people building AI earnestly believe that it could kill us all by the end of the decade," Coxon stated in his posts. "This is not a marketing stunt."

He described differing attitudes at the two labs. At OpenAI, he said, many have not fully internalized the risks. At Anthropic, the dangers are understood, but the company remains locked in a race because it believes others will not act responsibly.

Coxon warned that superhuman systems capable of hacking, rapid field revolutions, and acquiring power are approaching quickly. He told the Wall Street Journal that aggressive timelines could see capabilities spiral out of control by the end of next year.

Anthropic's Alignment Science Lead Evan Hubinger publicly agreed with the core concern, stating that researchers genuinely believe advanced AI could pose existential risks and estimating more than a 10 percent chance of human extinction from AI within the next decade.