Birmingham: Celine Naef vs Mary Stoiana

Platform comparison

Active sub-markets

Market context

The Birmingham tennis fixture between Celine Naef and Mary Stoiana, originally set for 4 June 2026, remains scheduled with settlement contingent on a completed match by 11 June. The 100% implied probability reflects either exceptionally high confidence in match completion or minimal trading activity; given the early scheduling window and lack of recent injury reports on either player, traders appear to be pricing in baseline tournament execution rather than expressing strong directional conviction about the outcome itself.

Naef, a Swiss player ranked outside the WTA top 100, and Stoiana, a Romanian competitor with comparable ranking status, represent the type of opening-round pairing typical of grass-court warm-up events preceding Wimbledon. Historical precedent suggests such early-round matches at established tournaments like Birmingham's Rothesay Classic carry high completion rates, though weather disruptions on grass courts and player withdrawals remain material risks. The settlement window's seven-day buffer accounts for potential rain delays common to June fixtures in the Midlands.

Traders should monitor the ATP and WTA injury report channels and Birmingham tournament announcements through early June for any withdrawal notices. Grass-court conditions and weather forecasts for the week of 2–4 June will influence match timing but are unlikely to trigger the 50-50 resolution unless delays extend beyond the settlement deadline. The current probability leaves minimal edge for either directional bet unless new information emerges regarding player fitness or tournament scheduling changes.

Methodology

We track Birmingham: Celine Naef vs Mary Stoiana on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Prediction Today is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on Prediction Today?

Zero. Prediction Today routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.