Resolution criteria

• Resolves YES if the ATP officially recognizes Carlos Alcaraz as the 2025 ATP Year-End No. 1 singles player (“ATP Year-End No. 1 presented by PIF”). Primary source: ATP’s year-end rankings press release and the ATP PIF Rankings (Singles) page for the week following the 2025 Nitto ATP Finals (held Nov 9–16, 2025). If ATP issues an official “clinched year-end No. 1” announcement before season’s end, the market may resolve YES at that time. Otherwise resolves NO. In any tie or later correction, we follow ATP’s final published determination. (atptour.com)

Background

• “Year-end No. 1” is based on the official PIF ATP Rankings (the weekly 52‑week system used for milestones like World No. 1), not the Live Race, though the Race is a useful predictor. (atptour.com)

• 2024 Year-End No. 1 was Jannik Sinner (example of the ATP’s year-end release). (atptour.com)

• As of Sep 8, 2025, Alcaraz won the US Open and reclaimed World No. 1. (apnews.com)

Considerations

• Players can clinch year-end No. 1 before the ATP Finals conclude (e.g., Sinner clinched on Oct 12, 2024); early ATP confirmation would settle this market. (atptour.com)

• ATP Finals points are included in the rankings and the Finals count as an additional event in the breakdown. (atptour.com)

• The ranking used for verification will be the first rankings run after the 2025 Finals (week of Nov 17, 2025). (atptour.com)