Polymarket Odds for Anthropic Fable Model by Month-End Fall to 38%

Polymarket’s implied probability that Anthropic will make a qualifying Fable model publicly available by Oct. 31 stood at 38% at 12:55 a.m. ET (04:55 UTC) Friday, Oct. 23, after falling 30% over the previous 24 hours.

For the market to settle “Yes,” a model’s name must contain “Fable” and its version number must be at least 5.2. Claude Fable 5.2, Claude Fable 5.3 and Claude Fable 6 meet those criteria; Claude Fable 5.1 and Claude Mythos 5.2 do not.

A version number of 5.2 or higher is not enough if the model’s name lacks “Fable,” while a Fable model below version 5.2 falls short of the cutoff.

Public beta access and an open public waitlist meet the availability requirement. Closed tests, private access and placeholder text without an accessible model do not qualify.

The contract rules give priority to Anthropic’s official information while allowing credible media coverage as a reference. The 38% figure is the market’s implied probability of a qualifying model becoming publicly available by month-end.