US Open ATP: Ben Shelton vs Carlos Alcaraz odds: Kalshi vs Polymarket
Tue, Sep 8, 2026, 8:30 PM ET · ATP tennis matches · $371k traded in 24h across both venues.
Carlos Alcaraz: Kalshi 78¢ vs Polymarket 77¢, +1.0 pp
Mid prices. A price is the market's probability: 78¢ means 78%. The gap is Kalshi minus Polymarket in percentage points.
Two separate exchanges, two accounts. Links may carry a referral code, which never changes what is shown. Disclosures.
-1.89¢ per $1, after fees
Buy Ben Shelton @ Kalshi 22¢, Carlos Alcaraz @ Polymarket 77¢
All outcomes
| Outcome | Kalshi bid / ask | Polymarket bid / ask | Gap |
|---|---|---|---|
| Ben Shelton | 21¢ / 22¢ | 23¢ / 24¢ | -2.0 pp |
| Carlos Alcaraz | 77¢ / 78¢ | 76¢ / 77¢ | +1.0 pp |
Price history, last 3 days
How this is matched
Games are matched across the two exchanges by league, team codes and date. Polymarket prices come from its live order book, Kalshi from its public API. Refreshed every 45 seconds.
What this is not
Read-only. Nothing here places or routes orders and nothing is advice. Fees, slippage and the time it takes to move money between venues are not in these numbers.