National Bank Open: Aryna Sabalenka vs Moyuka Uchijima

Platform comparison

Market context

Polymarket is pricing Aryna Sabalenka to advance past Moyuka Uchijima at about **98% YES**, which is consistent with a near-certain favourite in a one-off WTA match settled on **USDC** via **Polygon** conditional tokens. For a trader, the key point is that the contract pays on who advances, not on set score or game margin, so a straight-sets win, a retirement, or any completed win for Sabalenka all resolve the same way unless the market’s specific tie/cancellation clauses are triggered.

That probability sits well above most published tennis prices, where Sabalenka is described as a heavy favourite and widely quoted around the low 1.0x range, with one preview listing her at **1.054** and another at **1.06** against Uchijima’s double-digit underdog odds.[2][3] In practical terms, the market is reflecting the same basic read as bookmaker and preview markets: Sabalenka is the WTA No. 1 and Uchijima is the much lower-ranked player, so the main reason to doubt the YES side is not a normal upset but a non-standard settlement path.[3][4][6]

The live catalysts are procedural rather than tactical: the scheduled start, any revised order of play, and whether the match is actually completed within the settlement window. National Bank Open listings and odds feeds showed the fixture scheduled for 4 August 2026, while the market itself allows a 50-50 result if the match is cancelled, tied, or delayed beyond seven days without a winner, and if it starts but is not completed the conditional outcome rules still matter for resolution.[5][6] That means traders should watch official tournament updates and any match-status changes more closely than shot-by-shot form once play is underway.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews National Bank Open: Aryna Sabalenka vs Moyuka Uchijima across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.