This market will resolve to the highest 50% time horizon, as reported by METR as of April 30, 2026, for any AI model released on or before February 28, 2026.

50% time horizon is a measure of the length of tasks that AI can do: roughly, it is the time that humans take to complete software and computer tasks that AI 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% task horizon of 59 minutes.

Time horizon could vary based on the set of tasks used to measure it, so this market will be based on the time horizon for the most comprehensive set of tasks reported by METR. This will be ambiguous if METR stops publishing time horizons across all of their autonomy tasks and only publishes separate results for different subsets; I might N/A in that scenario.

Left bounds inclusive, right bounds exclusive.