By Jake Hari · prices as of September 1, 2026, 2:33pm ET (Tuesday afternoon)
Alexandra Eala walks onto Louis Armstrong Stadium tonight as the No. 17 seed, her highest seeding at a Grand Slam and, by the Philippine press's count, the highest any Filipino player has held, to open her US Open against qualifier Mary Stoiana. On Kalshi's US Open Women's Singles Winner board she is something stranger than a 17 seed: the busiest contract on the entire women's draw. More of her contract has changed hands than Aryna Sabalenka's, the top seed and two-time defending champion, by better than two to one. She trades level with Coco Gauff, the home favorite. And the price for all that activity is 3 cents bid, 4 cents ask, roughly where it has sat for three weeks.
That combination, the most-traded name and one of the cheapest prices, is the whole reason this page exists. Volume is the number everyone quotes and almost nobody reads correctly. A market can be busy because sharp money is fighting over a price, or busy because a lot of people want to own a piece of a story, and the two look identical in the volume column. They look completely different in the order book. Eala's order book has one number in it that settles the question, and I will get to it after the tape shows you where all this volume came from.
Every read on this page is built from Kalshi quotes pulled at 2:33pm ET on September 1; treat them as model estimates, not predictions of fact and not financial advice. Kalshi is a CFTC-regulated exchange and requires traders to be 18+ under its own platform policy; availability varies by state, and whether sports contracts like these count as sports bets a state can regulate is in active litigation after the Ninth Circuit's August 28 ruling, so check the platform's eligibility screen for your state before you do anything with these numbers.
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Tonight's Two Prices: A Worked Example With $100
Kalshi is pricing Eala twice today. The match contract, "Alexandra Eala wins" against Stoiana, is quoted at 79 cents bid and 80 cents ask, with Stoiana's side at 20 and 21. On an exchange like this, a contract pays a dollar if the thing happens and nothing if it doesn't, so a price in cents is just the crowd's live estimate of the chance: an 80-cent Eala match contract says roughly four in five. In payout terms, $100 on her match contract at 80 cents returns about $125 if she wins tonight and zero if she doesn't.
The title contract is the other price, and the one this page is about. At 4 cents, $100 buys 2,500 contracts, which become $2,500 if she is holding the trophy on September 12 and nothing otherwise. The gap between those two numbers is the tournament: tonight, then six more wins, through a road I will map further down.
Stoiana is the kind of first-round opponent a 17 seed expects. She played college tennis at Texas A&M, arrived at Flushing Meadows ranked No. 122, and won three qualifying matches to reach her first main draw, one of them over Yue Yuan, a match Kalshi also listed and has already settled in her favor. The two have met once, on a hard court in Landisville in 2024, and Eala won 7-5, 6-2. The 20-cent price on Stoiana is the market's way of saying a main-draw debut against a top-20 player is not a coin flip, and nobody has argued hard with that number: her side of the match contract has traded about 71,600 contracts, Eala's side about 40,400, and the quote sits at 80-20.
Eala's title contract has traded almost ten times what her side of tonight's match has, and that is where the story starts.
The Busiest Longshot On The Board
Here is the top of Kalshi's women's winner board sorted the way the exchange sorts it, by total contracts traded, with the price beside each name. Lifetime volume only ever grows, so I have paired it with open interest, the count of contracts still held right now, which tells you whether a market traded once and went quiet or is live today.
| Player (Seed) | Kalshi bid / ask | Lifetime contracts | Open interest | Last 24 hours |
|---|---|---|---|---|
| Alexandra Eala (17) | 3¢ / 4¢ | 374,091 | 307,071 | 40,565 |
| Coco Gauff (4) | 18¢ / 19¢ | 371,071 | 286,593 | 54,645 |
| Aryna Sabalenka (1) | 22¢ / 24¢ | 156,430 | 135,507 | 21,913 |
| Elena Rybakina (2) | 4¢ / 5¢ | 149,454 | 101,623 | 23,054 |
| Naomi Osaka (13) | 6¢ / 7¢ | 129,171 | 119,195 | 11,465 |
| Iga Swiatek (8) | 15¢ / 16¢ | 114,240 | 82,892 | 10,081 |
| Jessica Pegula (3) | 9¢ / 10¢ | 113,769 | 96,858 | 8,174 |
| Amanda Anisimova (10) | 3¢ / 4¢ | 84,221 | 76,817 | 22,924 |
Source: Kalshi market KXWTA-26USO, pulled September 1, 2026 at 2:33pm ET. Contract counts are rounded to the nearest whole contract.
Read the first two rows together. Gauff and Eala have traded within about 3,000 contracts of each other over the life of the market, and Gauff is the No. 4 seed, an American, and the second favorite. Eala has done it at one-fifth of Gauff's price. Then read the third row: the top seed, a two-time defending champion at this event, has traded less than half of what Eala has. If you only looked at the volume column you would think Eala was a contender the market was fighting over.
The open interest column is the one I would not over-read. Of the 374,091 Eala contracts ever traded, 307,071 are still open, an 82% hold rate, which sounds like conviction until you run the same division down the column: Gauff 77%, Sabalenka 87%, Osaka 92%. Holding is normal on a winner board this far from settlement. The better tell is what all those holders could sell into.
Where The Volume Came From: Washington
The first Eala contract on this board traded on August 3, at 10 cents, the same day she beat Jessica Pegula in the final of the DC Open for her first WTA title, having already gone through Qinwen Zheng, Leylah Fernandez, Elina Svitolina and Naomi Osaka that week. That result did what a title run does to a market that had no line on you: it created one, and outside a single 20-cent print the next morning, the contract has not traded above that opening price since.
Over the next three days, August 4 through 6, roughly 57,500 Eala contracts traded at an average price near 8 cents. By August 10 the average trade was under 5 cents, and by August 11 the contract was changing hands at 3 to 4 cents. Two weeks of Montreal and Cincinnati followed, a fourth round in Montreal that ended against Belinda Bencic and a third round in Cincinnati that ended against Anisimova, and the price settled into a band around 4 cents that it has since drifted down through: 3 to 4 cents on nearly every trade since the main draw began. The volume never slowed down. August 24 alone saw about 29,000 contracts trade. The three days since the main draw began, August 30 through this afternoon, have moved roughly 92,000 more, almost all of it between 3 and 4 cents.
Line those two facts up and you get the setup for everything below.
The more of her contract people bought, the lower the price went. Volume with conviction behind it pushes through the offers above it. This volume never pushed through the 5-cent wall.
The cleanest way to see how unusual that is sits one row down. Gauff's contract spent most of July and early August trading between 8 and 14 cents on a few hundred contracts a day. Then she won Cincinnati on August 23, beating Pegula in the final, and her volume did what Eala's did after Washington: about 23,000 contracts on August 23, 48,000 on the 24th. The difference is what happened to the quote. Gauff went from 14 cents that weekend to 16 by the end of the week, and after the 57,000 contracts that traded on August 31, she is quoted at 18 and 19 this afternoon. Similar buyer-heavy flow, a similar news trigger, a similar-sized surge; one price moved about five cents in nine days and the other price moved down.
The Liquidity Tell: 185 Contracts
Both crowds were buyers. Kalshi's trade tape records which side of each trade was the aggressor, the one who crossed the spread to get filled, and on Eala's contract about 81% of all volume was buyers lifting the offer. On Gauff's it was about 83%. So the buying pressure is not what separates the two markets. What separates them is who was standing on the other side, and how much they were willing to sell.
The bid depth is where the answer lives. A bid is a standing order to buy; the bid side of a book is what you can sell into if you ever want out. As of this afternoon, the best Eala bid, at 3 cents, has about 185 contracts behind it. The next rung down, at 2 cents, holds about 9,900, and the 1-cent rung about 11,150. Gauff's best bid, at 18 cents, has about 29,050 contracts behind it, with another 9,750 a cent lower. Sabalenka's 22-cent bid holds roughly 4,390, with about 2,870 more stacked in the four rungs beneath it.
Put those numbers against the volume. A market that has traded 374,091 contracts has 185 contracts of real demand at its quoted price. If you own $100 worth of Eala at 4 cents, that is 2,500 contracts, and the entire 3-cent bid absorbs 185 of them before your next sale prints at 2 cents, half of what you paid. Round-trip cost on a thin longshot is the subject of our Kalshi bid-ask spread guide, and Eala's book is the textbook case: one cent of spread is a quarter of the price, and the bid is too shallow for even a small position to lean on.
The offer side of her book tells you why the price never rose. There are about 1,500 contracts offered at 4 cents, then a wall: roughly 39,000 at 5 cents, another 14,500 at 6, and 29,800 more at 7. The price never averaged above a nickel on any day in the last three weeks, and today's book shows why: tens of thousands of contracts are still offered at 5 cents to anyone who wants them. Gauff's price had to climb five cents to keep finding sellers, which is what a book looks like when the offers thin out. Eala's never had to climb at all.
So the read on the "most-traded longshot" line is simple once you have seen the book. The volume is real, the money is real, and it is retail flow: a lot of people buying a small piece of a story and holding it. Market conviction would show up as bids stacked under the price and sellers backing away above it. Eala's book has neither.
What A 3-Cent Price Actually Says
A 3-to-4-cent contract is a 17-seed price at a Grand Slam, and on this board it is company she shares with better-credentialed names: Rybakina, the No. 2 seed, is quoted at 4 and 5 cents; Karolina Muchova, the No. 7 seed, at 3 and 4; Anisimova, the No. 10 seed and the player who beat Eala in the Cincinnati third round last month, at 3 and 4. Winning seven matches in a fortnight against this field is a 1-to-5-percent proposition for everyone outside the top four names, and the board is stacked with pennies to prove it: 13 of its 24 rows sit below 3 cents.
Her season is the reason she is on the board at all: a win over the defending champion Iga Swiatek on the way to the Wimbledon fourth round, the Washington title, a fourth round in Montreal, a third round in Cincinnati, and a ranking that now reads No. 18 a year after she won one US Open match from five match points down against Clara Tauson and went out to Cristina Bucsa in the second round. The results are what the 374,091 contracts were buying, and they are real. The sharper fact is who she shares the price with: the market quotes her at exactly the number it quotes Anisimova, the woman who beat her in Cincinnati, and a cent under Rybakina, the No. 2 seed. A 3-to-4-cent contract says the market rates her a real second-week threat and nothing more, and that price does not move much above a nickel until she beats the names in the next section.
One piece of arithmetic worth having before tonight: the title contract and the match contract are linked. If her chance of winning the tournament is about 4 cents and her chance of winning tonight is about 80, then a win tonight, with nothing else on the board changing, lifts the title price to about 5 cents on the math alone. Five cents is the ceiling the sellers have been defending. Whether the crowd pushes through it on a win is the first thing I will look at tomorrow morning.
The Draw Path The Price Is Quoting
Eala landed in the bottom half of the draw, the half the tennis press has been calling the brutal one, and specifically in Coco Gauff's quarter. Here is her path as the seedings project it, with each name's Kalshi title price beside it. The point of the column on the right is that a 4-cent title contract is really a quote on this whole ladder at once.
| Round | Projected opponent (seed) | That player's Kalshi title price |
|---|---|---|
| First Round (Tonight) | Mary Stoiana (qualifier) | not listed |
| Second Round | Oleksandra Oliynykova or Reese Brantmeier (wild card) | not listed |
| Third Round | Iva Jovic (14) or Magda Linette | Jovic 1¢ / 2¢ |
| Fourth Round | Coco Gauff (4) | 18¢ / 19¢ |
| Quarterfinal | Mirra Andreeva (5), Madison Keys (22), Daria Kasatkina or Paula Badosa | Andreeva 5¢ / 6¢; Keys 1¢ / 2¢; Badosa 0¢ / 1¢; Kasatkina not listed |
| Semifinal | Iga Swiatek (8) or Elena Rybakina (2) side | Swiatek 15¢ / 16¢; Rybakina 4¢ / 5¢ |
| Final | Aryna Sabalenka (1) or Jessica Pegula (3) side | Sabalenka 22¢ / 24¢; Pegula 9¢ / 10¢ |
Projected opponents follow the seedings; results in the early rounds will reshuffle the middle of this table. Kalshi lists 24 names on the winner board, so several possible opponents carry no title price at all.
The row that matters is the fourth round. The board's four most expensive contracts, Sabalenka, Gauff, Swiatek and Pegula, all sit somewhere on her road, and the first of them arrives in the fourth round, before she has played a quarterfinal. The likely third-rounder against Jovic, the 14 seed, is the first match on this road with a seed on the other side of the net, and the market has Jovic at a penny or two, cheaper than Eala despite the higher seeding. A win over Jovic does not change Eala's title price much, because the contract behind it is priced by Gauff.
The honest version of "what a 3-cent price means" is that it is the product of seven separate prices, and the biggest of them belongs to the No. 4 seed she would meet in the fourth round. For the full two-venue board, men's and women's, our US Open tennis odds page prices every seed side by side, and the men's champion verdict runs the same exercise on the other draw.
- US Open Mixed Doubles Odds: Kalshi's Three-Day Alcaraz Slide
- US Open Tennis Withdrawals 2026: 20 Out, Kalshi's Board
- US Open Tennis 2026 Odds: Where Kalshi And Polymarket Split
- National Bank Open Odds: 25 Seeds Gone, Shelton Alive
- Massachusetts Primary 2026: The One Race The Market Won't Call
How I Read This Board Tonight
Tonight's real test is whether a win creates bid support, because the pairing of this price with this volume is the cleanest example I have seen this year of what a busy market can hide. Anyone who scans the Kalshi board tonight will see Eala's name at the top of the activity sort and assume the market has a view. The clearer signal is the 5-cent wall, and the 185-contract bid is the receipt. Sabalenka, at less than half the volume, has more than 20 times the bid depth at her quoted price. Volume told you who the crowd loves; the book told you what the traders behind the quotes believe.
What I will look at tomorrow morning is the 3-cent bid. A bid that is 185 contracts deep on the day of a match she is 80% to win is a bid nobody is defending; if she wins comfortably and it is still under a few hundred contracts, the buyers were never planning to sell and the sellers never had to blink. The other number is the 5-cent offer wall, and Gauff's Cincinnati tape is the callback: her crowd bought through the sellers and the price had to move. If Eala's crowd does the same after a win, the contract finally trades like a contender's. If it doesn't, you will be looking at the same 4-cent quote on Thursday with 50,000 more contracts behind it, which is what the last three weeks have looked like.
If you came here from a sportsbook, the reason a 4-cent contract is not the same thing as a 4% chance you can sell back at 4 cents is the subject of our how prediction markets work explainer and the Kalshi odds guide; if tonight's match is the part you care about, the free expert picks hub is where our handicappers post the plays they are making, and the toolkit behind it starts with a free week trial.
Eala's night on Armstrong starts around 8:40pm ET. The most-traded contract on the women's board will still be the most-traded contract on the women's board tomorrow, whatever happens. What tomorrow decides is whether it is finally priced by traders or still priced by fans.
