The Prediction Markets

Boulter vs Ishii

Starts in 16 hKickoff
Traded
$2K
Venues
Polymarket, Kalshi
Prices updated
1 min ago
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What the markets expect

Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner 62.5%

Next is Boulter at 52.6%. The venues differ most on Boulter (Polymarket 50.5%, Kalshi 55%), a 4.5-point gap.

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, the oldest 4 min ago. Ages are as of when this page was built.

  • Polymarket
  • Kalshi
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
62.5%
Polymarket 62.5%polled, 4 min agoBest Yes 79¢ on Polymarket, $100 pays $127 (1.27x)
Polymarket
Contract
Set Handicap: Sayaka Ishii (-1.5) vs Katie Boulter (+1.5)
Last price
62.5%
As of
Polled 4 min ago
Buy Yes
79¢
Sell Yes
46¢
$100 on Yes pays
$127 (1.27x)
Trade this on Polymarket
Boulter
52.6%
Polymarket 50.5%polled, 4 min agoKalshi 55%polled, 1 min agoBest Yes 51¢ on Polymarket, $100 pays $196 (1.96x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii
Last price
50.5%
As of
Polled 4 min ago
Buy Yes
51¢
Sell Yes
50¢
$100 on Yes pays
$196 (1.96x)
Volume
$1K
Trade this on Polymarket
Kalshi
Contract
Katie Boulter
Last price
55%
As of
Polled 1 min ago
Buy Yes
55¢
Sell Yes
48¢
$100 on Yes pays
$182 (1.82x)
Volume
$1K
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 48¢, at or below the cheapest ask of 51¢.

Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
50.5%
Polymarket 50.5%polled, 4 min agoBest Yes 53¢ on Polymarket, $100 pays $189 (1.89x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
Last price
50.5%
As of
Polled 4 min ago
Buy Yes
53¢
Sell Yes
48¢
$100 on Yes pays
$189 (1.89x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
50%
Polymarket 50%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Set Handicap: Katie Boulter (-1.5) vs Sayaka Ishii (+1.5)
Last price
50%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
3¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
50%
Polymarket 50%polled, 4 min ago
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 2 Winner
Last price
50%
As of
Polled 4 min ago
Buy Yes
—
Sell Yes
—
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
50%
Polymarket 50%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Total Sets: O/U 2.5
Last price
50%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
3¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
49%
Polymarket 49%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Match O/U 22.5
Last price
49%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
1¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
49%
Polymarket 49%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Match O/U 21.5
Last price
49%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
1¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
49%
Polymarket 49%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Match O/U 23.5
Last price
49%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
1¢
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48.5%
Polymarket 48.5%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 O/U 9.5
Last price
48.5%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
—
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Show 7 more outcomes
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48.5%
Polymarket 48.5%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 O/U 10.5
Last price
48.5%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
—
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48.5%
Polymarket 48.5%polled, 4 min agoBest Yes 97¢ on Polymarket, $100 pays $103 (1.03x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 O/U 8.5
Last price
48.5%
As of
Polled 4 min ago
Buy Yes
97¢
Sell Yes
—
$100 on Yes pays
$103 (1.03x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48%
Polymarket 48%polled, 4 min agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 2 O/U 9.5
Last price
48%
As of
Polled 4 min ago
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48%
Polymarket 48%polled, 4 min agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 2 O/U 8.5
Last price
48%
As of
Polled 4 min ago
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
48%
Polymarket 48%polled, 4 min agoBest Yes 96¢ on Polymarket, $100 pays $104 (1.04x)
Polymarket
Contract
Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 2 O/U 10.5
Last price
48%
As of
Polled 4 min ago
Buy Yes
96¢
Sell Yes
—
$100 on Yes pays
$104 (1.04x)
Trade this on Polymarket
Sayaka Ishii
42%
Kalshi 42%polled, 1 min agoBest Yes 48¢ on Kalshi, $100 pays $208 (2.08x)
Kalshi
Contract
Sayaka Ishii
Last price
42%
As of
Polled 1 min ago
Buy Yes
48¢
Sell Yes
42¢
$100 on Yes pays
$208 (2.08x)
Volume
$31
Trade this on Kalshi
Completed Match
33.5%
Polymarket 33.5%polled, 4 min agoBest Yes 66¢ on Polymarket, $100 pays $152 (1.52x)
Polymarket
Contract
Completed Match
Last price
33.5%
As of
Polled 4 min ago
Buy Yes
66¢
Sell Yes
1¢
$100 on Yes pays
$152 (1.52x)
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: wtatennis.com
Kalshi
Kalshi resolves via:
Kalshi (CFTC-regulated exchange), source: WTA
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 31, 2026, 6:30 AM UTC on Polymarket and Nov 7, 2026, 1:30 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.

  • Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner
  • Boulter
  • Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner

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 Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner 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 "Boulter vs Ishii". Pan Pacific Open, Qualification: Katie Boulter vs Sayaka Ishii Set 1 Winner leads at 62.5%. Next is Boulter at 52.6%. $2K has traded across 17 outcomes on Polymarket and Kalshi. The market is expected to resolve by Nov 7, 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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