Next Mythos Model (5.3+) released by December 31, 2026: odds and prices

This market will resolve to "Yes" if Anthropic's next Mythos model (5.3+) is released between market creation and the specified date (ET), as described below. Otherwise, this market will resolve to "No".

A qualifying model must have a name or model identifier that includes "Mythos" and be designated as version 5.3 or higher, regardless of capitalization or surrounding prefixes, suffixes, dates, or descriptors. For example, a version 5.3 or higher named in the same manner as Claude Mythos 5.1 or Claude Mythos 5.2 would qualify, including a new whole-number generation such as Claude Mythos 6, while models whose name does not include "Mythos" or which retain a version designation below 5.3, such as Claude Mythos 5.2 or Claude Fable 5.2, will not qualify.

A qualifying model will be considered released once Anthropic officially announces its release and makes it available to external users, including where access is limited to organizations approved through Anthropic's verification or trusted-access programs (such as the Cyber Verification Program or Project Glasswing), as was the case for Claude Mythos 5.2, released November 9, 2026. General public availability is not required. Internal testing, or access granted only to pre-release testers or evaluators without an official release announcement, will not qualify, and an announcement of future availability will not count until the model is actually available to such users.

The primary resolution source for this market will be official information from Anthropic, with additional verification from a consensus of credible reporting.