Anthropic Launches Fable 5.2 and Mythos 5.2 Models Days Before Nasdaq IPO

Anthropic released Claude Fable 5.2 and Claude Mythos 5.2 on Monday, the newest versions of its two top model classes. The company says both generate outputs up to 30 percent faster than their 5.1 predecessors, and that Fable 5.2 uses fewer tokens than Fable 5.1 on challenging tasks at medium effort. Fable 5.2 is also cheaper: $8 per million input tokens and $40 per million output tokens, down from $10 and $50 for Fable 5.1.

Anthropic still points most users elsewhere. It recommends starting with Claude Opus 5.5 for most coding and knowledge work, reserving Fable and Mythos for the hardest requests. Fable is included for up to 50 percent of weekly usage limits on Pro plans and standard Team seats, while Mythos 5.2, which carries fewer safety restrictions for cybersecurity and life-sciences work, stays limited to verified organizations. Mythos debuted in April and Fable two months later, in June.

The release comes days before Anthropic's planned Nasdaq listing. IFR reported the IPO launches Tuesday morning; other reports describe Tuesday as the start of the roadshow, with pricing expected after the U.S. market close on November 18 and a raise of $80 billion to $100 billion. Anthropic has not confirmed the timetable, and no price range was on file as of Monday.

Valuation is the open question. One analysis expects a listing at about $1.5 trillion, with some investors pushing toward $1 trillion after last week's AI selloff; the Financial Times has reported talks of $1.25 trillion to $1.75 trillion. Morningstar argues Anthropic is well placed to capture value in an AI-driven economy, pointing to its API business, while subscriptions made up only about 20% of revenue in the first half of 2026, leaving the company more exposed to metered usage.

What to watch: the price range when the roadshow opens, where final pricing lands against the reported valuation band, and whether Fable 5.2's lower pricing lifts usage enough to offset lower revenue per token.