Resolution criteria on PolyGram: This is a market to predict who will win a women's tennis Calendar Grand Slam in 2026. This market resolves to the single woman player who wins the Women's Singles titles at all four Grand Slam tournaments in 2026. The relevant 2026 Grand Slams are the Women's Singles tournaments in the 2026 Australian Open, French Open, U.S. Open, and Wimbledon. For the purpose of this market, a tournament victory is valid regardless of whether the final was won via a walkover, a mid-match retirement, or a standard completed match. If at any point it becomes impossible for a listed player to achieve a Calendar Grand Slam in 2026 (e.g.
PolyGram is an on-chain prediction market where you trade YES or NO outcome shares with real USDC on Polygon. For this market, buy YES if you believe the event will happen, or NO if you think it won't. Your maximum loss is your stake — winning shares pay $1.00 each at resolution. Unlike sportsbooks, there is no house edge: prices are set by supply and demand from other traders and reflect the crowd's real-time probability.
Market outcomes
| Aryna Sabalenka | 0% YES | 100% NO |
| Elena Rybakina | 1% YES | 99% NO |
| Naomi Osaka | 0% YES | 100% NO |
| Jessica Pegula | 0% YES | 100% NO |
| Elina Svitolina | 0% YES | 100% NO |
| Emma Raducanu | 0% YES | 100% NO |
| Victoria Azarenka | 0% YES | 100% NO |
| Other | 0% YES | 100% NO |
A women's tennis Calendar Grand Slam in 2026 would require a single player to win the Australian Open, French Open, Wimbledon, and U.S. Open within the same calendar year. The current 0% implied probability on Polymarket's order book reflects the extreme rarity of this achievement; no woman has completed a Calendar Grand Slam since Margaret Court in 1970, and only five women have ever done so in the Open Era or its predecessor. The feat demands not only sustained excellence across different surfaces and conditions but also freedom from injury across nine months of elite competition.
The historical context frames why markets price this outcome so conservatively. Serena Williams came closest in the modern era, winning three majors in 2015 and 2016 but never completing the calendar sweep. Even dominant players like Steffi Graf (1988) and Court faced formidable odds. Current top-ranked players would need to maintain peak performance through four separate tournaments whilst navigating the physical toll of professional tennis, where even minor injuries or tactical adjustments by opponents can derail campaigns.
Key catalysts for traders include the 2026 tournament schedules, injury reports for top players heading into the season, and performance at early 2026 majors—particularly the Australian Open in January, which will provide the first concrete data on form. Surface-specific strengths matter considerably; a player must excel on hard courts, clay, and grass simultaneously, a combination few possess. Monitoring player retirements and career longevity through 2025 will also signal which competitors remain viable contenders for such an ambitious target.
Resolution is handled by the UMA optimistic oracle on Polygon. A proposer submits the outcome, a two-hour dispute window opens, and if no one stakes a counter-claim the payout is final. Contested outcomes escalate to UMA token-holder voting. Payouts clear in USDC to the winning side.
The mechanics for trading "Who will win a women's Calendar Grand Slam in 2026?" are the same as any other PolyGram event contract. Each YES share resolves to $1 if the event happens, or $0 if it doesn't. The current price between 0¢ and 100¢ is the market's probability estimate, set live by the order book.
$1.6M in lifetime turnover and $398K of resting liquidity puts this market in the top 2% by volume for tennis contracts on PolyGram. Order-book depth is exceptional — among the deepest order books in the category.
Last 24 hours alone saw $26 in turnover, consistent with the market's lifetime daily-average pace.
The market has been open for 4 months — the price has had time to stabilise as new information arrived.
Higher-volume markets tend to have tighter spreads and faster price discovery — meaning the displayed YES/NO percentages are more likely to reflect the true crowd-implied probability rather than a single trader's directional view.
Resolution is handled by the UMA optimistic oracle on Polygon. A proposer submits the outcome, a 2-hour dispute window opens, and if uncontested the payout is final. Contested outcomes escalate to UMA token holders.
This prediction market is scheduled to close on 31 December 2026. After the resolving event occurs, settlement typically clears within 24 hours once the UMA optimistic oracle confirms the outcome. All payouts are in USDC on the Polygon network.
To trade on this prediction market, create a free PolyGram account at polygram.ink, deposit USDC via Polygon, and place a YES or NO order on the outcome you believe in. You can learn more on our how-it-works page. Your maximum loss is limited to your stake — there is no leverage or margin.
When the outcome is determined, winning YES shares pay out $1.00 each in USDC, while losing shares pay $0. Settlement is handled by the UMA optimistic oracle on Polygon — a proposer submits the result, a two-hour dispute window opens, and if uncontested, payouts are distributed automatically. You can withdraw your winnings to any Polygon wallet.
Prediction-market positions can lose 100% of staked capital. Outcomes are uncertain by definition — historical accuracy of crowd-implied probabilities is high in aggregate but not for any single market. PolyGram does not provide investment advice. Trade only with capital you can afford to lose.
Regulatory status varies by jurisdiction. Germany, the United States, and most EU countries treat Polymarket-style event contracts under one of three frameworks: financial derivative, gambling product, or unregulated novel asset. Consult local counsel before trading.
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