National Bank Open: Karen Khachanov vs Terence Atmane

Platform comparison

Market context

Karen Khachanov’s second-round meeting with Terence Atmane at the National Bank Open is priced by the market at 56% for Khachanov, which is broadly in line with the conventional sportsbook view. Aggregated bookmaker odds listed by TennisTemple put Khachanov around 1.68 decimal and Atmane around 2.18, implying a modest edge for the Russian rather than a dominant favourite[1]. Kalshi is quoting the same match at 71¢ for Khachanov and 67¢ for Atmane on separate contract lines, so its display is in cash terms rather than direct percentage form; by contrast, Polymarket-style markets typically show a single yes/no probability, while Betfair and Smarkets are better read via their exchange prices and commission-adjusted returns rather than headline odds. On a simple read-through, 56% leaves room for a competitive match, not an upset-heavy setup[1][3].

The historical frame is also fairly balanced: Atmane is listed just behind Khachanov in ATP ranking terms in the TennisTemple feed, and preview pieces for this pairing have leaned towards a longer match rather than a routine straight-sets result[1][7]. That matters because prediction markets on tennis often move less on name recognition than on surface, draw position and whether the favourite has already been tested in earlier rounds. For platform comparison, the same edge can look different depending on format: decimal odds on Betfair or a fixed-price contract on Kalshi may both point to the same underlying view, but fees and regional KYC access can change the effective price a user receives.

The main catalysts are straightforward: whether the match starts on schedule, whether there is a late withdrawal, and whether either player has any fitness issue before first ball. The market is already set to resolve to 50-50 if the match is not played, ends in a tie, or is delayed beyond seven days without a winner, so any cancellation risk is material. Schedules on the tournament and live-score feeds should be watched closely, because the event is in the second round and the official match time can still shift with court order or weather[8][9][12].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read National Bank Open: Karen Khachanov vs Terence Atmane from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

UK Frequently Asked Questions

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Polymarket vs Betfair Exchange: which is better for UK prediction trading?

Betfair Exchange offers UKGC regulation, GBP settlement, and potentially tax-free winnings — but focuses on sports and politics only. Polymarket has deeper liquidity, 0% platform fee, global event coverage, and crypto/geopolitical markets Betfair doesn't offer. For UK traders: Betfair for regulated GBP sports markets; Polymarket for broader, global prediction events.

Is Kalshi available in the UK?

Kalshi is a US CFTC-regulated prediction exchange. UK residents can create accounts but must use USD and US payment methods. Kalshi's product range overlaps with Polymarket but with lower liquidity on most contracts. For UK traders, Polymarket typically offers better prices due to higher global volume.