**Traders assign an 89.5% probability to “No” on Trump endorsing JD Vance for president before 2027 because public statements and timing signals point against an imminent formal endorsement.** President Trump has repeatedly described any 2028 succession decision as “way too early,” including in direct Oval Office comments on August 6, 2026, where he praised Vance but declined to commit. This stance aligns with his broader pattern of publicly elevating both Vance and Secretary of State Marco Rubio while privately telling some donors “we need to elect JD.” Advisers emphasize that Trump has not settled on a preferred successor and favors delaying any public move to preserve leverage and avoid lame-duck dynamics ahead of the midterms. Recent reporting from August 2026 shows consistent private openness to Vance alongside continued public hedging, with no formal endorsement issued. Other Republican figures, such as Sen. Ted Cruz on August 25, have noted that the party has not coalesced around any single candidate, reinforcing uncertainty about near-term resolution. These factors—explicit public caution, deliberate ambiguity between Vance and Rubio, and the short window remaining in 2026—underpin the strong trader consensus against a pre-2027 endorsement.