Anthropic releases first frontier models since Amodei's call for slowdown as IPO buzz builds

Anthropic on Monday released two new artificial intelligence models, Claude Fable 5.2 and Claude Mythos 5.2, as the company readies for a potentially historic IPO that could take place as soon as next week.

Fable 5.2 and Mythos 5.2 are Anthropic's most advanced offerings, and the company said they generate outputs 30% faster than their predecessors. The models also cost 20% less than the 5.1 generation, and will be available for $8 per million input tokens and $40 per million output tokens, the company said.

The launch marks the first time that Anthropic has released so-called "frontier" models since its CEO, Dario Amodei , called to slow down the pace of AI development in September . Anthropic said the models went through rigorous safety and alignment testing, and that the company developed new evaluations and post-launch monitoring tools ahead of the release.

"We called for pacing, not pausing," Dianne Penn, Anthropic's head of product management for research, told CNBC in an interview.

Anthropic has to balance its safety efforts with intense commercial and competitive pressures, a tension that the company highlighted in the extensive risk factors section of its prospectus late last month. And as executives prepare to kick off Anthropic's IPO roadshow , they'll have to convince investors that their approach is the right one.

The company is aiming for a valuation of $1 trillion to $1.5 trillion in its offering, as CNBC previously reported , down from a target of $2 trillion that had been floated in recent months.

Anthropic first introduced Mythos in April, and it limited the rollout to a select group of organizations because of the model's advanced cybersecurity capabilities. The company introduced Fable , a publicly available version of Mythos with additional safeguards, two months later.

The models — particularly Mythos — captivated Wall Street and government officials alike, and they helped to fuel Anthropic's meteoric rise this year. The company said in its amended prospectus that it generated $33.24 billion in revenue for the nine months ended Sept. 30, up roughly 1,200% from the same period last year.

Penn said Fable 5.2 is primarily intended for "power users or power use cases" since it excels at complex, open-ended technical work. Other models like Claude Opus 5.5 , which Anthropic released in September, are better suited for daily tasks, so Penn said users should turn to Fable 5.2 when they need to tackle hard problems in engineering, mathematics and robotics.