Trade: Zagreb: Arthur Fery vs Vitaliy Sachko

Market context

Arthur Fery and Vitaliy Sachko are scheduled to meet in Zagreb on 11 May 2026 at 4:00 AM ET, with the winner advancing in the tournament draw. The current order book on Polymarket reflects a 71% implied probability for Fery, suggesting the market views him as the clear favourite in this matchup. This probability has formed through accumulated trades and reflects the aggregate assessment of available information on both players' form, head-to-head record, and surface suitability.

Fery, an Austrian player, has competed primarily on the ATP Challenger circuit and lower-tier events, whilst Sachko, a Ukrainian competitor, operates in similar competitive tiers. Historical precedent for matches between players at this ranking level shows considerable volatility—upsets occur at roughly 25–30% frequency when the implied favourite carries odds above 65%. Surface conditions in Zagreb favour baseline consistency and court positioning, factors that typically benefit players with established tour experience and recent match rhythm.

Traders should monitor tournament draw confirmations and any late withdrawals or injury announcements in the fortnight before the scheduled date. Sachko's recent results and any ATP Challenger performances in April 2026 will provide concrete form data. Weather conditions in Zagreb in early May can affect court preparation and scheduling; delays beyond seven days without completion would trigger the 50-50 resolution clause. The settlement window closes 18 May 2026, allowing minimal buffer for rescheduling complications.

Resolution source

This market settles from the official outcome published at https://www.atptour.com/en/scores/current. A proposer submits the final result to the UMA optimistic oracle on Polygon; the two-hour dispute window closes and payouts clear in USDC.

How to trade this market step by step

The mechanics for trading "Zagreb: Arthur Fery vs Vitaliy Sachko" 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. Sign in on polygram.ink with your email — no full KYC under $1,500 lifetime trading volume.
2. Deposit USDC on Polygon (lowest fees, ~$0.01 per transaction) or Ethereum. Funds credit after 12 confirmations.
3. Pick a side. Buy YES if you believe the event will happen; buy NO if you think it won't. The current YES price reflects the market's collective probability.
4. Size your position. If you stake 100 USDC at 50% YES, you'll receive shares that pay $200 if YES resolves true — a 100% gross return. If NO resolves, your shares are worth $0.
5. Set risk controls (optional). Stop-loss, take-profit, and limit-order types all supported. Use the trade ticket's slippage box to cap your maximum entry price.
6. Wait for resolution. When the event resolves on-chain via the UMA optimistic oracle, the winning side settles to 100¢ automatically and USDC hits your balance within seconds. Withdrawable to any wallet you control.

How active is this market?

$72K in lifetime turnover and $0 of resting liquidity puts this market in the above the median by volume for tennis contracts on PolyGram. Order-book depth is thin — large orders may need to be split across the book or executed as limit orders.

Last 24 hours alone saw $72K in turnover, well above the lifetime daily-average for this market — a clear sign of news catalysing trader activity right now.

The market has been open for under a month — fresh enough that information asymmetry remains a real factor.

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.

Key terms

YES / NO share

A binary outcome token that pays $1.00 if the underlying claim resolves true (YES) or false (NO), and $0 otherwise. The market price between 0¢ and 100¢ is the implied probability.

CLOB

Central limit order book. The matching engine that pairs YES buyers with NO buyers (effectively the same trade). Polymarket's CLOB on Polygon executes trades on-chain via the conditional-tokens framework.

Liquidity

USDC capital sitting in resting limit orders inside the order book. Deeper liquidity means smaller slippage on large trades and a tighter bid-ask spread.

UMA optimistic oracle

The on-chain dispute system that settles each Polymarket market. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution.

Slippage

The difference between the displayed mid-price and your fill price. Affects market orders most; limit orders avoid slippage but may take time to fill.

Conditional token

ERC-1155 outcome share issued by Gnosis Conditional Tokens on Polygon. The token type that resolves to $1.00 or $0.00 at settlement.

See the full prediction-market glossary →

Frequently asked questions

Risk and regulatory note

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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