The Prediction Markets

Donald vs Romano

Starts in 1 h 56 minKickoff
Traded
$9K
Venues
Polymarket, Kalshi
Prices updated
just now
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What the markets expect

Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5 70%

Next is Donald at 53.6%. Polymarket and Kalshi agree within 1 point on each matched outcome.

Odds by venue

Consensus blends each venue’s last price, weighted by how much has traded there. Best Yes price is the cheapest ask across venues, and the payout is what a winning $100 stake returns before fees. Open a row for each venue’s contract name, bid and ask, and how closely their rules match.

Prices come from our regular polls of each venue. Ages are as of when this page was built.

  • Polymarket
  • Kalshi
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
70%
Polymarket 70%polled, 43s agoBest Yes 72¢ on Polymarket, $100 pays $139 (1.39x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
Last price
70%
As of
Polled just now
Buy Yes
72¢
Sell Yes
69¢
$100 on Yes pays
$139 (1.39x)
Trade this on Polymarket
Donald
53.6%
Polymarket 53.5%polled, 43s agoKalshi 54%polled, 43s agoBest Yes 54¢ on Polymarket, $100 pays $185 (1.85x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano
Last price
53.5%
As of
Polled just now
Buy Yes
54¢
Sell Yes
53¢
$100 on Yes pays
$185 (1.85x)
Volume
$7K
Trade this on Polymarket
Kalshi
Contract
Matthew William Donald
Last price
54%
As of
Polled just now
Buy Yes
54¢
Sell Yes
53¢
$100 on Yes pays
$185 (1.85x)
Volume
$2K
Trade this on Kalshi
Partial parity

Payoffs match in ordinary outcomes; see the rule differences below the table.

No arbitrage: the best bid elsewhere is 53¢, at or below the cheapest ask of 54¢.

Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
51.5%
Polymarket 51.5%polled, 43s agoBest Yes 53¢ on Polymarket, $100 pays $189 (1.89x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 1 Winner
Last price
51.5%
As of
Polled just now
Buy Yes
53¢
Sell Yes
50¢
$100 on Yes pays
$189 (1.89x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
51.5%
Polymarket 51.5%polled, 43s agoBest Yes 54¢ on Polymarket, $100 pays $185 (1.85x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Game Spread +/-0.5
Last price
51.5%
As of
Polled just now
Buy Yes
54¢
Sell Yes
49¢
$100 on Yes pays
$185 (1.85x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
51%
Polymarket 51%polled, 43s agoBest Yes 52¢ on Polymarket, $100 pays $192 (1.92x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Match O/U 21.5
Last price
51%
As of
Polled just now
Buy Yes
52¢
Sell Yes
50¢
$100 on Yes pays
$192 (1.92x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
50%
Polymarket 50%polled, 43s ago
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 2 Winner
Last price
50%
As of
Polled just now
Buy Yes
—
Sell Yes
52¢
Trade this on Polymarket
Completed Match
49.5%
Polymarket 49.5%polled, 43s agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Completed Match
Last price
49.5%
As of
Polled just now
Buy Yes
97¢
Sell Yes
2¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
49%
Polymarket 49%polled, 43s agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Match O/U 23.5
Last price
49%
As of
Polled just now
Buy Yes
97¢
Sell Yes
1¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
48.5%
Polymarket 48.5%polled, 43s agoBest Yes 55¢ on Polymarket, $100 pays $182 (1.82x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 9.5
Last price
48.5%
As of
Polled just now
Buy Yes
55¢
Sell Yes
—
$100 on Yes pays
$182 (1.82x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
48%
Polymarket 48%polled, 43s agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 2 O/U 10.5
Last price
48%
As of
Polled just now
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Show 8 more outcomes
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
48%
Polymarket 48%polled, 43s agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 2 O/U 8.5
Last price
48%
As of
Polled just now
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
48%
Polymarket 48%polled, 43s agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 2 O/U 9.5
Last price
48%
As of
Polled just now
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Filippo Romano
47%
Kalshi 47%polled, 43s agoBest Yes 47¢ on Kalshi, $100 pays $213 (2.13x)
Kalshi
Contract
Filippo Romano
Last price
47%
As of
Polled just now
Buy Yes
47¢
Sell Yes
46¢
$100 on Yes pays
$213 (2.13x)
Volume
$208
Trade this on Kalshi
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
44.5%
Polymarket 44.5%polled, 43s agoBest Yes 46¢ on Polymarket, $100 pays $217 (2.17x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Match O/U 22.5
Last price
44.5%
As of
Polled just now
Buy Yes
46¢
Sell Yes
43¢
$100 on Yes pays
$217 (2.17x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
38.5%
Polymarket 38.5%polled, 43s agoBest Yes 40¢ on Polymarket, $100 pays $250 (2.50x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Total Sets: O/U 2.5
Last price
38.5%
As of
Polled just now
Buy Yes
40¢
Sell Yes
37¢
$100 on Yes pays
$250 (2.50x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
33.5%
Polymarket 33.5%polled, 43s agoBest Yes 35¢ on Polymarket, $100 pays $286 (2.86x)
Polymarket
Contract
Set Handicap: Matthew William Donald (-1.5) vs Filippo Romano (+1.5)
Last price
33.5%
As of
Polled just now
Buy Yes
35¢
Sell Yes
32¢
$100 on Yes pays
$286 (2.86x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
29%
Polymarket 29%polled, 43s agoBest Yes 30¢ on Polymarket, $100 pays $333 (3.33x)
Polymarket
Contract
Set Handicap: Filippo Romano (-1.5) vs Matthew William Donald (+1.5)
Last price
29%
As of
Polled just now
Buy Yes
30¢
Sell Yes
28¢
$100 on Yes pays
$333 (3.33x)
Trade this on Polymarket
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
25%
Polymarket 25%polled, 43s agoBest Yes 28¢ on Polymarket, $100 pays $357 (3.57x)
Polymarket
Contract
Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 10.5
Last price
25%
As of
Polled just now
Buy Yes
28¢
Sell Yes
22¢
$100 on Yes pays
$357 (3.57x)
Trade this on Polymarket

No cross-venue arbitrage right now: on every matched outcome, the best bid on one venue is at or below the cheapest ask on the other. Find markets with open spreads

Mostly the same bet: two differences

Where they differ

  • If the match is postponed: Kalshi resolves to a fair price if the match does not start within 48 hours of the scheduled time (tennis: not finished within two weeks); Polymarket stays open until the match is played and resolves 50-50 only if it is cancelled with no make-up (tennis: ~14 days).
  • Kalshi requires a ball to be played and pays the winner; Polymarket pays the player who advances, including on retirement. A pre-match walkover is a fair price on Kalshi, 50-50 on Polymarket.
Polymarket
Polymarket resolves via:
UMA optimistic oracle, source: atptour.com
Kalshi
Kalshi resolves via:
Kalshi (CFTC-regulated exchange), source: ATP
Show full rule comparison
  • If the match is postponed: Kalshi resolves to a fair price if the match does not start within 48 hours of the scheduled time (tennis: not finished within two weeks); Polymarket stays open until the match is played and resolves 50-50 only if it is cancelled with no make-up (tennis: ~14 days).
  • Kalshi requires a ball to be played and pays the winner; Polymarket pays the player who advances, including on retirement. A pre-match walkover is a fair price on Kalshi, 50-50 on Polymarket.
  • Trading closes Oct 30, 2026, 8:00 AM UTC on Polymarket and Nov 6, 2026, 9:30 AM UTC on Kalshi.

Summarized from each venue’s published rules; the venue’s own rules page is the final word.

How the odds have moved

The top 3 outcomes on both venues, with the consensus between them. Hover for exact values.

  • Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5
  • Donald
  • Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5

Order books

Each venue’s resting orders for the selected outcome’s Yes contract, side by side. Top of book streams live; depth refreshes every 15 seconds.

Polymarket

Open on Polymarket ↗

Top of book

Connecting
Best bid
—
Spread
—
Best ask
—

Waiting for the first live quote…

Depth · top 8 levels

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Recent trades

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Kalshi

Kalshi doesn’t list Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5 for this event.

What your stake buys

Enter a stake to see where it buys the most after fees, using each venue’s live order book.

$
Buy

Loading both order books…

Buys at the asks resting now (taker orders), cheapest after fees first, from order-book snapshots up to 15 seconds old. Fees: Kalshi 0.07 × price × (1 − price) per share, rounded up to the cent; Polymarket 0.05 × price × (1 − price) per share (sports rate). Fee calculator. Estimates only, not advice.

About this market

Live prediction market odds for "Donald vs Romano". Florence: Matthew William Donald vs Filippo Romano Set 1 O/U 8.5 leads at 70%. Next is Donald at 53.6%. $9K has traded across 18 outcomes on Polymarket and Kalshi. The market is expected to resolve by Nov 6, 2026.

Questions

What does the consensus price mean?

It is the price of a Yes contract that pays $1 if the outcome happens. A 14¢ price means traders put the chance near 14%. Where two venues list the same outcome, we blend their last prices, weighting the venue with more trading volume more heavily (neither counts for less than a quarter). When only one outcome can win, each venue’s prices add up to a little over 100% (its margin); the fair chance removes that margin so the outcomes add up to exactly 100%.

How is the payout worked out?

A Yes contract pays $1 if it wins, so at the best ask a $100 stake buys 100 ÷ ask contracts. At 18¢ that is about 555 contracts, paying $556 (5.56x) if Yes happens. Venue fees and price slippage on larger orders are not included.

Why do the venues show different prices?

Each venue has its own traders, fees and order book. Contracts can also settle on slightly different terms, which is why each row lists how closely the rules match.

Is a price gap an arbitrage?

Only when you can buy Yes on one venue below what someone pays for Yes on the other, after fees, and both contracts settle the same way. We show the executable bid and ask so you can check.

How fresh are these prices?

Venue prices refresh every few minutes, and the order book and live quotes stream continuously. Each venue’s card shows when we last observed it.

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