Polymarket Traders Wager on Fourth Anthropic Deadline Extension for Claude Fable 5 Model Access

Polymarket participants have assigned a 77% probability to Anthropic extending paid-plan access to its Claude Fable 5 model beyond the 19 July deadline, representing a 33-point increase as the cutoff date approaches. The prediction market contract, which has accumulated more than $57,000 in trading volume, will settle affirmatively if the artificial intelligence company announces a qualifying extension beyond Saturday.

The elevated odds reflect an established pattern of behaviour from Anthropic. The company has already postponed the deadline on three separate occasions, moving the original 22 June cutoff to 7 July, subsequently to 12 July, and most recently to 19 July. Each extension has been announced mere hours before the scheduled termination.

Fable 5, which represents Anthropic’s most sophisticated generally available model, launched on 9 June with an intended two-week promotional window before transitioning to usage-credit-only billing. Subscribers on Pro, Max, Team and qualifying Enterprise plans can presently utilise the model for up to 50% of their weekly usage limits without incurring additional charges.

Upon conclusion of the promotional period, access will require prepaid credits priced at $10 per million input tokens and $50 per million output tokens. This pricing structure marks the first instance of a frontier artificial intelligence laboratory implementing usage-based billing for a consumer-facing model. Anthropic has stated its intention to restore Fable 5 as a standard subscription feature once adequate computing capacity becomes available.

The successive deadline extensions occur against a backdrop of competitive pressure from OpenAI’s GPT-5.6 Sol model, which delivers benchmark performance comparable to Fable 5 whilst commanding substantially lower operational costs. A related Polymarket contract assigns a 68% probability to Anthropic announcing permanent paid-plan access for the model, whilst a separate contract indicates 84% odds of the company releasing a new Mythos-class model by 30 September.