Will Alexander Bublik win the 2026 Men's US Open?
Crossbook compares what two exchanges, Polymarket and Kalshi, charge for the same event, and publishes a permanent scored record of its own forecasts under published rules.
Both venues are priced below, side by side.
Informational only. Not trading or investment advice. Prices may be delayed or inaccurate, and a difference between venues can be an artifact — how this is measured.
Data may be delayed. These prices have not refreshed recently, so treat them as a last known reading rather than a current quote.
How each venue defines this
Each exchange's own settlement text, quoted as written. Where they differ, the difference is usually why the prices do.
Settles Sep 13, 26
The 2026 U.S. Open tennis tournament is scheduled for August 23 - September 13, 2026. This market will resolve to the player that wins the 2026 U.S. Open Men’s Singles Tournament. If at any point it becomes impossible for a listed player to win the 2026 U.S. Open Men’s Singles Tournament per the rules of the tournament, the corresponding market will resolve to “No”. If the 2026 U.S. Open Men’s Singles Tournament is cancelled, postponed after October 31, 2026, or there is otherwise no winner declared within that timeframe, this market will resolve to “Other”. The primary resolution source w…
Settles Sep 14, 26
If Alexander Zverev wins the 2026 US Open Men's Singles professional tennis tournament, then the market resolves to Yes.
Settlement basis
A person confirmed these two markets ask the same question. Their settlement documents have not been compared, so treat the price difference as unverified rather than as a like for like gap.
Confirmed as the same question: Will Alexander Bublik win the 2026 Men's US Open?
Crossbook forecast
- 13.0%against a market price of 0.5% at the timeOpen
Logged 29 Aug 2026, 03:34 UTC
- The tournament is already in progress (started Aug 23, today is Aug 29), so pre-tournament base rates are only a starting point; mid-event survival sharply updates odds for anyone still alive.
- The 22-point cross-venue spread (0.5% polymarket vs 23% kalshi) strongly suggests the polymarket book is a stale pre-tournament resting book while kalshi's $40k of 24h volume reflects live information — most plausibly that Bublik has advanced deep into the draw (e.g., quarterfinal or better) and possibly that favorites have been eliminated from his half.
- I discount kalshi's 23% somewhat because Bublik has never beaten the true elite tier in best-of-five at Slams, and winning two or three more matches against likely Sinner/Alcaraz-caliber opposition is harder than a thin, momentum-driven book may imply; landing near 12–14% respects both the live signal and his underlying level.
- If instead the kalshi price is itself stale or a mislabeled contract, 0.5–2% is the right range — this ambiguity is why confidence is low and I weight heavily toward the middle rather than fully trusting either venue.
What would change it: Confirmed draw information showing Bublik is already eliminated (estimate drops to ~0) or that he is in the semifinal/final with top seeds out (estimate rises toward 25–35%).
Context
Kalshi prices this at 28% while Polymarket has it at 1%, a gap of 27.3 points on the same question. A gap that wide usually means the two contracts are not asking quite the same thing, so the settlement terms below are the first thing to check.
Volume over the last 24 hours is active, at about $63,981 on the busier venue. It closes in 4 days. Prices this close to resolution move on news rather than on reassessment.
Related markets
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