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WTA Grand Slam on Kalshi
If Victoria Mboko wins a tennis major (the Australian Open, the French Open, Wimbledon, or the U.S. Open) after Issuance and before Dec 31, 2027, then the market resolves to Yes.
Settles on: ESPN, The New York Times, Reuters, the Associated Press.
Market says (typical open contract)
49%
Median YES price across 24 open contracts, 10 Nov 2026 09:57 UTC.
Real-world odds
—
No independent base rate yet. Until we connect one (sportsbook consensus, forecasts, the score), the market's own price is the best public forecast, and the fee sits on top of it.
Luck needed meter
98% 😈
Mostly luck. The market itself expects the favorite to lose this often; the fee is the only certainty.
The cover charge
| If you buy at | Fee per contract | On $50 | Win rate to break even |
|---|---|---|---|
| 30¢ | 1.5¢ | $2.45 | 31.5% |
| 49¢ (now) | 1.7¢ | $1.79 | 50.7% |
| 50¢ | 1.8¢ | $1.75 | 51.7% |
| 70¢ | 1.5¢ | $1.05 | 71.5% |
| 90¢ | 0.6¢ | $0.35 | 90.6% |
Resting orders pay no fee on this series. Formula: 7% × contracts × price × (1 − price), rounded up, on orders that take liquidity. Break-even assumes you hold to settlement; trading out early pays the fee twice.
Open contracts right now
| Contract | YES price | Implied | Fee at this price | Real-world odds | Luck needed | Volume | Closes |
|---|---|---|---|---|---|---|---|
| Tennis Grand Slam in 2027: Alexandra Eala · Alexandra Eala | 29¢ | 29% | 1.4¢ | — | 57% | 17 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Aryna Sabalenka · Aryna Sabalenka | 44¢ | 44% | 1.7¢ | — | 89% | 4 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Iga Swiatek · Iga Swiatek | 39¢ | 39% | 1.7¢ | — | 78% | 2 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Elena Rybakina · Elena Rybakina | 50¢ | 50% | 1.7¢ | — | 99% | 2 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Victoria Mboko · Victoria Mboko | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Naomi Osaka · Naomi Osaka | 35¢ | 35% | 1.6¢ | — | 70% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Marta Kostyuk · Marta Kostyuk | 50¢ | 50% | 1.8¢ | — | 100% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Madison Keys · Madison Keys | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Mirra Andreeva · Mirra Andreeva | 48¢ | 48% | 1.7¢ | — | 97% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Linda Noskova · Linda Noskova | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Karolina Muchova · Karolina Muchova | 50¢ | 50% | 1.8¢ | — | 100% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Jessica Pegula · Jessica Pegula | 40¢ | 40% | 1.7¢ | — | 79% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Jasmine Paolini · Jasmine Paolini | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Iva Jovic · Iva Jovic | 36¢ | 36% | 1.6¢ | — | 72% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Elina Svitolina · Elina Svitolina | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Emma Navarro · Emma Navarro | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Elise Mertens · Elise Mertens | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Ekaterina Alexandrova · Ekaterina Alexandrova | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Diana Shnaider · Diana Shnaider | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Coco Gauff · Coco Gauff | 40¢ | 40% | 1.7¢ | — | 80% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Belinda Bencic · Belinda Bencic | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Anastasia Potapova · Anastasia Potapova | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Anna Kalinskaya · Anna Kalinskaya | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
| Tennis Grand Slam in 2027: Amanda Anisimova · Amanda Anisimova | 49¢ | 49% | 1.7¢ | — | 98% | 0 | Dec 31, 04:59 UTC |
Who actually wins this market
- Whoever posts the resting orders and collects the spread without paying a fee.
- The venue, on every fee.
- Not, on average, the person clicking buy because the chart is going their way. That was us.
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