UFC 331: Casey O'Neill vs. Eduarda Moura (Women's Flyweight, Early Prelims) odds: Kalshi vs Polymarket
Sat, Sep 19, 2026, 5:00 PM ET · UFC fights · $0 traded in 24h across both venues.
Casey O'Neill: Kalshi 61¢ vs Polymarket 62¢, -1.0 pp
Mid prices. A price is the market's probability: 61¢ means 61%. 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.
-4.19¢ per $1, after fees
Buy Casey O'Neill @ Kalshi 62¢, Eduarda Moura @ Polymarket 39¢
All outcomes
| Outcome | Kalshi bid / ask | Polymarket bid / ask | Gap |
|---|---|---|---|
| Casey O'Neill | 59¢ / 62¢ | 61¢ / 62¢ | -1.0 pp |
| Eduarda Moura | 37¢ / 41¢ | 38¢ / 39¢ | +0.5 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.