This market will resolve according to the calendar date (ET) on which Anthropic's next Claude Sonnet model is made available to the general public. Claude Sonnet refers to a model by Anthropic explicitly named Sonnet. Qualifying models include Claude Sonnet 5.1, Claude Sonnet 5.5, Sonnet 6, or any other Sonnet variants. Models under any other name, such as Opus, Haiku, Fable, or Mythos, will not qualify, unless the model is explicitly and officially named Sonnet by Anthropic. A qualifying model must be launched and publicly accessible, including via open beta or open rolling waitlist signups. A closed beta or any form of private access will not suffice. The release must be either clearly defined and publicly announced by Anthropic as being accessible to the general public or otherwise made publicly accessible and explicitly labeled within the company's official website. Labeling errors, placeholder text, or version names displayed on the website that do not correspond to a model that is actually accessible to the general public will not qualify. The primary resolution source for this market will be official information from Anthropic, with additional verification from a consensus of credible reporting.