**The closely contested 53.5% implied probability for “Yes” on António Guterres leaving the UN Secretary-General post by December 31, 2026, reflects uncertainty around the final months of his second term amid an active succession process.** Guterres’s mandate concludes on that date under standard UN procedures, yet traders appear to weigh the risk of an earlier departure driven by Security Council dynamics. The 2026 selection process, formally launched in late 2025, has advanced through nominations, interactive dialogues, and initial straw polls in the Council, with eight candidates under consideration and P5 members holding veto power. Divisions among permanent members, including U.S. opposition to any temporary extension beyond December 31 and differing preferences for successors such as Rafael Grossi, introduce the possibility of deadlock that could generate institutional or personal pressure on the incumbent. Recent developments, including Guterres’s continued public engagements on multilateral reform, conflicts, and BRICS diplomacy through mid-September 2026, underscore his active role but also highlight the narrow window before term end. A resignation announcement, health-related exit, or sudden political impasse could shift odds sharply toward “Yes,” while smooth progress toward a Security Council recommendation and General Assembly appointment would support stability through December and favor “No.” Historical precedent shows most secretaries-general serve full terms without early departure, yet the current contested environment keeps the outcome finely balanced.