This market will resolve to the highest 50% time horizon, as reported by METR, for the first Claude Opus 5 model to appear on METR's graph. Claude Opus 5.1 or 6 counts for the purpose of this market, if 5 is skipped. 4.6 or 4.7 would not count. Sonnet would not count.
50% time horizon is a measure of AI autonomy based on the length of tasks that AI can do: roughly, it is the time that humans take to complete tasks that an AI system can successfully do 50% of the time. See METR's "Measuring AI Ability to Complete Long Tasks" for the technical definition. Claude 3.7 Sonnet, released in February 2025, was the leading model with a 50% horizon of 59 minutes.
Left bounds inclusive, right bounds exclusive.
See also:
/Bayesian/gpt-52-pro-metr-time-horizon
/Bayesian/gemini-3s-50-time-horizon-per-metr
/Bayesian/gemini-3-pro-metr-50-time-horizon
/Bayesian/claude-sonnet-46s-metr-50-time-hori
/Bayesian/claude-sonnet-5-metr-50-time-horizo
/Bayesian/claude-opus-5-metr-50-time-horizon
/Bayesian/grok-420s-metr-50-time-horizon
/Bayesian/grok-5s-50-time-horizon-per-metr
1,000