Elena Rybakina beat Aryna Sabalenka 6-4, 5-7, 6-2 on Saturday, September 12, 2026, at Arthur Ashe Stadium, for her first US Open title and her third major. The match ran 2 hours and 21 minutes. Kalshi's match market, the one this page priced at 12:05 a.m. Friday at Sabalenka 57¢ bid, 58¢ ask, closed at 6:38 p.m. ET and settled Rybakina at $1.00 three minutes later; the price history below was pulled at 8:56 p.m. ET on September 12, 2026, and re-pulled on the morning of September 16, 2026, and both contracts are finalized. The log itself cannot change, and did not; two cells in the table below and one row in the title board were corrected to the captions' own rules on the second pull, and the log is identical. The last print before four o'clock had Sabalenka at 59¢. At 4:16 p.m. she was 64¢. By 4:38 she was 35¢, and the market spent the rest of the afternoon trying to decide whether that first quarter-hour or the next two sets was the truth.
The original edition of this page said the board was not pricing the rivalry, which stood 7-7 on hard courts; it was pricing a fortnight of Sabalenka in New York and one Thursday night on which she did not face a second break point. That read was right about what the market was doing and wrong about whether the market should have been doing it, and the price history of the match shows the exact minute the market gave the read up, the exact minute it took it back, and the second, at 6:09 p.m. with a set apiece, when the largest fill in the market's life went through on the side that was about to win. The score first, then the pre-match argument graded against it, then the price history.
How Rybakina Won It
The match turned on a serve that was not working and a return that was. Per the WTA's match report, Rybakina landed 27 percent of her first serves in the opening set and won it anyway, 6-4, breaking for 3-2. The break came on a Sabalenka double fault, and Sabalenka, per ABC's wire report, drew a code violation immediately afterward for launching a ball into the stands. CBS Sports' live report counted three unforced errors and one double fault from Rybakina in that set against 15 unforced errors from Sabalenka.
The second set was the one the favorite's backers were paying for. Rybakina's first-serve percentage climbed to 61, she had two break points and converted neither, and at 4-5 she saved two set points to hold for 5-5. Sabalenka broke two games later and took the set 7-5. One set each, and the market went back to almost exactly where it had started the day; that number is in the price history below, and it is the most telling one on this page.
Then the third set, which was not close. Rybakina broke for 2-1, broke again for 5-2 with a volley winner, and closed the championship with her 12th ace of the match. By the WTA's count she dropped just three points on serve in the set. By the AP's count she had 12 break chances across the match and converted three, and got fewer than half of her first serves in. Three of 12 on break points did not matter, because in the third set she barely lost a point behind her own serve. The chair umpire, per CBS, requested crowd courtesy and no camera flashes during the third set; Sabalenka smashed a racket after hugging Rybakina at the net, per the AP's report.
"It's tough to find the words right now," Rybakina said afterward, per the WTA. "Honestly, I didn't expect [anything] like this coming from this tournament." She retired from her Cincinnati quarterfinal with an injury before New York and came from a set down in consecutive matches, against Zheng Qinwen and Coco Gauff, to reach the final. "I was coming here for the last 10 years, and it was never successful," she said. Sabalenka's line, per the same report: "Overall, I should be happy with the level I played, and there are lots of things to take from this tournament." Her 19-match winning streak at the US Open, which began at the 2024 tournament, is over. On Monday, September 14, as was settled when Rybakina beat Zheng on Wednesday, Rybakina took the No. 1 ranking Sabalenka had held for 99 consecutive weeks, one short of 100; the final did not decide that, only the trophy. The winner's check was $5.5 million, the largest in Grand Slam history per the AP, against $2.8 million for the runner-up. Rybakina is the third woman since 2000 to win the Australian Open and the US Open in the same season, after Angelique Kerber in 2016 and Sabalenka in 2024, and, per Tennis Majors, the first player from Kazakhstan to win the US Open or to hold the No. 1 ranking.
So a 27-percent first-serve set won, two set points saved at 4-5, and a third set in which the favorite won two games. Now hold that against what the market said on Friday.
What The Pre-Match Read Got Wrong, And What It Got Right
Friday's edition of this page laid out what 57 had to be right about, in two parts. Here is how each part aged.
The first part was the serve. The price, this page argued, was a bet that Thursday's version of Sabalenka's serve, one break point faced in two sets against Jessica Pegula, would travel to Saturday, and that Rybakina's, which Gauff broke at least twice, would not. That read was half right. Rybakina's first serve deserted her for a full set, as forecast. Sabalenka's did not hold up either: she was broken for 3-2 on a double fault, made 15 unforced errors in the first set, and was broken twice in the third. As a forecast of the consequence, the read was wrong in the way that matters. Rybakina won the set her serve abandoned her in. The page had written that the 42 percent of Rybakina's service points that start with a second serve were "where Sabalenka earns her money," and on Saturday Rybakina lived on second serves for a full set and won the set. The serve read priced the right variable and the wrong player's response to it.
The second part was the fortnight against the rivalry, and here the page's own doubt was the right call. Among the things it said the 43 had to be wrong about was whether Sabalenka's 19-0 at this tournament since 2024 was "mostly a draw fact, with three Pegula wins among them … rather than a surface-and-venue fact that travels to a Rybakina final." On Saturday it did not travel. One final does not prove a 57 was mispriced; it does show that the thing 57 had to be right about, the fortnight outweighing the rivalry, did not hold on the day. The rivalry's tour-level record, per the Wikipedia rivalry page, is now Sabalenka 10-8 overall, and the split underneath it has moved the way Friday's 7-7 hinted it would.
| Year | Event | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2025 | Wuhan | QF | Hard | Sabalenka | 6-3, 6-3 |
| 2025 | WTA Finals | Final | Hard | Rybakina | 6-3, 7-6(0) |
| 2026 | Australian Open | Final | Hard | Rybakina | 6-4, 4-6, 6-4 |
| 2026 | Indian Wells | Final | Hard | Sabalenka | 3-6, 6-3, 7-6(6) |
| 2026 | Miami | SF | Hard | Sabalenka | 6-4, 6-3 |
| 2026 | US Open | Final | Hard | Rybakina | 6-4, 5-7, 6-2 |
Tour-level matches only; exhibitions excluded. After Saturday the head-to-head is Sabalenka 10-8 overall, Rybakina 8-7 on hard courts, Rybakina 5-2 in finals and 2-1 in Grand Slam finals, per the rivalry record.
The row to sit with is the last one, because of what it does to the rows above it. Rybakina's last three wins over Sabalenka are the 2025 WTA Finals title match, the 2026 Australian Open final and the 2026 US Open final: the three biggest matches they have played in that span, and she has won all three. Sabalenka's three wins in the same stretch came in a WTA 1000 quarterfinal, a WTA 1000 final and a WTA 1000 semifinal. Friday's page put the 7-7 in a headline as the record "Where It Counts"; the headline undersold it. Where it counts most, in finals, it was 4-2 and is now 5-2. The 64¢ that printed at 4:16 p.m. Saturday was the highest price Sabalenka traded at in the market's life, above any pre-match print, against an opponent who had beaten her in two of their last three finals, including the last one played at a major.
What the page got right was narrower and worth stating plainly, because it is the part a reader could have used. It did not call the match. It said the only price on the page worth arguing with was "the 44¢ a Rybakina buyer really pays," that the case for it was seven hard-court wins none of which came in Queens, and that a reader who believed the hard-court record was the truth was getting a coin flip at 44 and needed her to be a 46. It also refused to pretend the sportsbooks had a line when they did not; by Saturday afternoon they did, and they sat within a few points of Kalshi. CBS Sports' betting preview, stamped 3:01 p.m. ET Saturday, carried DraftKings' moneyline at an implied 59 percent on Sabalenka and 46 percent on Rybakina with the vig included, roughly 56 and 44 with it stripped out, against Kalshi's 59¢ and 43¢ an hour later; the book had the favorite a few cents cheaper than the exchange. Kalshi's own preview, published Saturday, had traders at 58 percent on Sabalenka. Nobody with money on the line had this at even. The hard-court record did.
The consensus was 58 or 59 at four o'clock. What the market did with that number over the next two and a half hours is the part no preview could have written.
The Price History: 64¢ In The First Set, 1¢ At The Close
On Kalshi each woman was her own yes-or-no contract under the event ticker KXWTAMATCH-26SEP12SABRYB, paying $1.00 on a win and nothing otherwise, with the price in cents standing in for probability; the plain-English guide to prediction markets covers the mechanics. The rules settle the match "after a ball has been played," and a ball was played, so the fair-price and postponement clauses never came into it. What follows is the Sabalenka yes contract, from one pull of Kalshi's public trade tape at 8:56 p.m. ET Saturday, every fill since listing. The Rybakina contract is its mirror, and where it adds something it is noted.
| Time (ET) | What the price history shows | Sabalenka yes | Rybakina yes |
|---|---|---|---|
| Fri. 11:59 P.m. | Last print of Friday | 57¢ | 44¢ |
| Sat. 3:59 P.m. | Last print before 4 p.m. | 59¢ | 43¢ |
| Sat. 4:14 To 4:18 P.m. | 160 fills at 62¢ or higher, 53,360 contracts; high of 64¢ at 4:16 | 64¢ | 39¢ |
| Sat. 4:38 P.m. | First print at 35¢ | 35¢ | 65¢ |
| Sat. 5:00 To 5:10 P.m. | 938,016 contracts in ten minutes, range 31¢ to 40¢ | 34¢ | 66¢ |
| Sat. 5:45:55 P.m. | Low of the first two sets: three fills at 19¢ totalling 203 contracts | 19¢ | 77¢ |
| Sat. 5:56 To 5:57 P.m. | 548,380 contracts in two minutes, 47¢ to 61¢ | 61¢ | 39¢ |
| Sat. 6:09:47 P.m. | 259,194 contracts printed at 57¢ with the taker selling; 273,440 Rybakina contracts printed at 43¢ the same second with the taker buying | 57¢ | 43¢ |
| Sat. 6:17 P.m. | First print at 25¢ | 25¢ | 71¢ |
| Sat. 6:29 P.m. | First print at 10¢ | 10¢ | 93¢ |
| Sat. 6:31 P.m. | First print at 3¢ | 3¢ | 97¢ |
| Sat. 6:38:03 P.m. | Last print; market closed 6:38:08 | 1¢ | 99¢ |
All prices are the yes contract on each side, from Kalshi's public trade tape pulled at 8:56 p.m. ET on September 12, 2026. Rybakina's column is her own leg's print in the same window, not 100 minus the Sabalenka price: the low of the window in the 4:14 and 5:56 rows, the high of the minute in the 5:45 row, the last print of the window elsewhere. The price history records prices, not points; the set boundaries below come from the timestamps on CBS Sports' live blog, which posted the first set at 5:02 p.m., the second at 5:59 p.m. and the match at 6:37 p.m. Re-pulled on the morning of September 16, 2026: the log is identical, 37,848 Sabalenka fills and 26,340 Rybakina fills, and every row above was re-checked against it; two Rybakina cells, 4:38 and 6:29, were corrected to the last print of their minute (65¢ and 93¢), and the rest stood.
What Moved Since September 13
Nothing on the board, and that is the point of checking. A re-pull of both legs of KXWTAMATCH-26SEP12SABRYB on the morning of September 16 returned the same 9,998,469 Sabalenka contracts and 7,296,220 Rybakina contracts, the same last prints of 1¢ and 99¢, and a settlement stamp of 6:41:08 p.m. ET on September 12, three minutes after the close. Open interest at settlement, which Friday's page had no number for on the match legs, was 5,329,963 contracts on the Sabalenka leg and 3,453,027 on the Rybakina leg; every one of those was paid out or written off that evening, and the market has not printed since. The title board, KXWTA-26USO, is finalized on all 31 contracts, and its six busiest rows are the table further down, with one row corrected: Jessica Pegula's 467,441 contracts, which the September 12 edition had ranked behind Naomi Osaka's 427,094, were the sixth-busiest on the board all along, so Pegula's row replaces Osaka's.
What moved was around the board. The ranking caught up on Monday, September 14: per Tennis365's rankings roundup, Rybakina to No. 1 on 9,902 points and Sabalenka to No. 2 on 7,875, with Pegula 610 back of her and Gauff another 21 behind that, and the WTA's own rankings note closing Sabalenka's run at the top at 99 weeks. The handover itself had been settled on the court on Wednesday, when Rybakina beat Zheng; the trophy contract and the ranking were never the same bet, which is why the 57¢ on Saturday's board was never a price on No. 1. And the men's final this page pointed to on Saturday night has settled its own way: Alexander Zverev beat Ben Shelton in four sets on Sunday, the Zverev contract paid $1 at 5:57 p.m. ET on September 13, and the two legs of that match market did 23,003,480 contracts between them, against 17,294,689 for this one. The men out-traded the women by a third, a day later, and in both finals the heavier leg was the one that settled at zero: Shelton's 14,113,258 contracts against Zverev's 8,890,222, Sabalenka's ten million against Rybakina's 7.3 million. The difference is that the men's favorite held.
Back to the Saturday price history, which is unchanged and still the reason this page exists.
Start at the top, because the first row is the one the market would most like back. The last print before four o'clock was 59¢, two cents above Friday's snapshot, and in the quarter-hour from 4:14 the price went up, not down: 160 fills at 62¢ or higher, 53,360 contracts, a high of 64¢ at 4:16 p.m. It was not one clean slide. The price dipped to 46¢ at 4:23, was back at 64¢ by 4:31, and then went for good: 40¢ at 4:35, 35¢ at 4:38, a minute before CBS's blog posted Rybakina's break for 3-2. The market gave up the fortnight read once, fast, in the 4:30s, around one break of serve, against a player whose own first serve was landing about a quarter of the time.
The first set ended around five o'clock, and the ten minutes that followed were the busiest of the match to that point: 938,016 contracts between 5:00 and 5:10 p.m., in a range of 31¢ to 40¢, last print 34¢. Our own afternoon snapshot of the board, at 5:04 p.m., caught it at 31¢ bid, 32¢ ask. The price printed 20¢ at 5:15 and then spent most of the next half hour in the 30s. The low of the first two sets came later, in a five-minute stretch that is the wildest on the price history before the third set: from 39¢ at 5:40 up to 55¢ at 5:41, down to 36¢ at 5:42, and to 19¢ at 5:45:55 p.m., three fills totalling 203 contracts, before it was back at 37¢ a minute later. The low came in the second set with Rybakina a set up; the price history cannot place it on a point, and I will not. A Sabalenka buyer at 19¢ was buying a two-time defending champion at less than one in five.
Then the row that makes the whole tape worth reading. Between 5:56 and 5:57 p.m., three minutes before CBS posted Sabalenka's 7-5 second set, 548,380 contracts went through and the price went from 47¢ to 61¢. CBS posted the set at 5:59. So at one set each, the market had Sabalenka at 57¢ to 61¢. She had been 59¢ at four o'clock. Nearly two hours of tennis, a set in which the favorite was broken while her opponent served at 27 percent, a set in which the favorite held two set points at 5-4, lost both, and broke for it anyway, and the market's net conclusion was: no new information, back to the pre-match number. That is either the market being admirably disciplined about small samples or the market not having watched the first set, and one third set cannot settle which.
The first ten minutes of the third set ranged from a 40¢ print at 6:06 to 61¢ prints in the 6:07 and 6:08 minutes, and then came the 6:09:47 p.m. print, the largest in the history of either leg. On the Sabalenka side, 259,194 contracts at 57¢ with the taker on the sell side; on the Rybakina side, in the same second, 273,440 contracts at 43¢ with the taker buying. Whether that was one account or many, the price history does not say. What it does say is that with the third set a few games old, someone was willing to pay 43¢ for Rybakina, the same price she had traded at in the last minute before four o'clock, in a size the market had never seen. The premium on the Rybakina side alone was about $117,600 for a $273,440 payout. Twenty-eight minutes later the contract settled at a dollar. Three seconds before it, a 40,584-contract fill at 57¢ had gone the same way, seller-initiated; 38 seconds after it, a 40,584-contract fill at 55¢ was a buyer, and that one did not end well.
From there the price history reads like a scoreboard: 25¢ at 6:17; 10¢ at 6:29; 3¢ at 6:31; 528 fills at 1¢ totalling 419,640 contracts as the last games played out, and a final print of 1¢ at 6:38:03 p.m., five seconds before the market closed.
Two more numbers from the same pull, because Friday's page made a claim they answer. That page noted the match market was 40 minutes old, had 4,362 contracts through it, and that "whoever is trading size on Saturday's final is doing it in the title contracts," where open interest ran to 373,000 to 410,000 a name. That was true on Friday and badly wrong by Saturday evening. The Sabalenka leg finished with 9,998,469 contracts traded across 37,848 fills; the Rybakina leg with 7,296,220 across 26,340. Of the Sabalenka leg's ten million, 895,308 traded before four o'clock on Saturday and 9,103,160, 91 percent, traded from 4 p.m. on. The volume-weighted average price of every in-match Sabalenka fill was 33.5¢; of every in-match Rybakina fill, 66.4¢. The market spent the afternoon, on average, at two-to-one the other way from where it opened.
The number to take from this page91. That is the share of a ten-million-contract market that traded while the match was on. The pre-match market, the one every preview quoted, was the other 9 percent.
That is the match market. The title contract this page said was where the size lived settled the same way, a few minutes later, and its own tape has one detail worth the detour.
The Title Board Settled From 42¢
The US Open women's champion market, KXWTA-26USO, quoted within a cent of the match market all Friday and through Saturday afternoon, as it had to with two names left. Rybakina's title contract last printed on Friday at 43¢ and at 42¢ at 3:59 p.m. Saturday; Sabalenka's touched 60¢ in the final minute before four o'clock, after a 20,000-contract buy at 58¢ at 3:07 p.m., the largest pre-match Saturday fill on either finalist's title contract; two Rybakina title fills at 6:24:56 p.m., 22,160 and 20,633 contracts, were bigger once the match was live. Both contracts closed at 6:37:49 p.m. ET and Kalshi settled them at 6:42:58 p.m., four minutes and 50 seconds after the match market closed. Rybakina yes, everyone else no.
| Contract (KXWTA-26USO) | Settled | Contracts traded, lifetime | Open interest, final |
|---|---|---|---|
| Aryna Sabalenka | No | 1,208,930 | 527,120 |
| Coco Gauff | No | 1,100,827 | 604,710 |
| Elena Rybakina | Yes | 1,085,403 | 432,957 |
| Emma Navarro | No | 592,340 | 559,848 |
| Alexandra Eala | No | 585,711 | 423,465 |
| Jessica Pegula | No | 467,441 | 336,951 |
Top six contracts on the title board by lifetime volume, from the same 8:56 p.m. ET pull, unchanged on the September 16 re-pull. Every contract on the board is finalized; the match markets under KXWTAMATCH-26SEP12SABRYB finished at 9,998,469 contracts (Sabalenka) and 7,296,220 (Rybakina), so the final's match market out-traded the entire title board.
More US Open boards: Shelton vs Zverev odds, Sunday's men's final, settled (Zverev in four; the title board had Alexander Zverev 56¢ bid, Ben Shelton 42¢ bid at 8:56 p.m. ET Saturday, before a ball was struck) · Kalshi picks today, whose Friday edition led with Sabalenka's overnight title-contract jump · US Open women's title board (the full field board)
The detail is the third row. The champion's contract was the third-most-traded name on her own board. Sabalenka's traded 123,000 more, which a favorite's usually does, but Gauff's traded more than Rybakina's too, and Gauff lost in the semifinal to the woman who won the tournament. Three contracts crossed a million; two of them settled at zero. On a board of 31 contracts and one winner, the money was where the story was, not where the trophy went, and the sum of the title board's six busiest contracts, about five million, is less than a third of what the two-leg match market did in one afternoon.
What The 44¢ Was Worth
Friday's edition ran the fee math on both sides before either had settled. Now both have. A reader who took Kalshi's 44¢ ask on Rybakina on Friday, 100 contracts, paid $44.00 plus a trading fee of 0.07 × 100 × 0.44 × 0.56, which is $1.72 before Kalshi rounds the fee up to $1.73. The position paid $100.00 on Saturday evening. Net profit $54.27 on a $45.73 outlay, fee included. A reader who took the 58¢ on Sabalenka, 100 contracts, paid $58.00 and a $1.71 fee and collected nothing. The fee schedule has the formula, and it is the reason the break-even on the Rybakina side was 46 percent rather than 44: the page's Friday question was whether she was a 46, and one final does not answer it; it only shows which side of 46 the day fell on.
The price history also settles a question Friday's page could only pose, and it is the one a reader can actually use. Friday's page said the difference between the two contracts was depth, that the 43¢ ask on Rybakina was eight contracts deep, and that anyone trading size would slip a cent. That was the market at 12:05 a.m. Friday, 40 minutes after listing, with 4,362 contracts through both legs combined. Here is the depth timeline the price history gives after that. At 3:02 a.m. Saturday, 118,811 contracts filled at 58¢ in one print. At 1:48 p.m. Saturday, 87,474 at 58¢. At 3:43 p.m., 54,053 on the Rybakina side at 43¢, 17 minutes before four o'clock. At 6:09:47 p.m., 273,440 at 43¢ in one second. The market that could not fill nine contracts at the touch on Friday morning was taking six-figure prints at a single price by three in the morning on Saturday and a quarter-million by the third set. The practical lesson is about when: a Kalshi match market is thin in its first hour after listing and nowhere near thin by the morning of the match, and it is deepest of all while the match is on. If you want to trade a final in size, wait for the book to fill after listing; you do not have to wait for the first serve. For the pre-match line itself, the live odds screen is where to compare the major books' number against the exchange's as the books post it.
Where The Rivalry Sits Now
Friday's page ended on the 7-7, and on the case for Rybakina being "seven hard-court wins, none of which came in Queens." It is eight now, and one came in Queens, in a final, against the two-time defending champion, with the first serve landing a quarter of the time in the set that decided the tone. The market priced the last two weeks and the rivalry priced the last two years, and for one Saturday the rivalry's answer was the one that paid. Sabalenka's 99 weeks at No. 1 ended on Monday, September 14, a week short of a round number; her two Grand Slam final losses in 2026 were both to the woman replacing her. Our Australian Open women's final show in January 2023, before the first major final these two ever played, flagged how Sabalenka had handled the nerves in her US Open semifinal the previous September, "walking a tightrope" against Iga Swiatek. Three and a half years on, her own line, per the WTA, that she "should be happy with the level" she played is the most honest reading of Saturday: the level was there for a set and a half, and the other player won the points that were worth the most.
The men settled it their way on Sunday: Alexander Zverev beat Ben Shelton from a title board that had them 56¢ and 42¢ on Saturday night, almost the same shape as the women's board at 3:59 p.m. Saturday, 60 and 42, and that time the favorite held. If Saturday is any guide to the next final you price, the number to watch is not the pre-match price but what the market does in the first 20 minutes of play, which is where this one went from 59¢ to 64¢ to 35¢. If pricing a single final is not your game, OddsShopper's free expert picks are the conventional route, and the US Open odds comparison across Kalshi, Polymarket and the sportsbooks has how the exchanges and the books priced the whole field before it narrowed to these two; the daily Kalshi picks hub grades the panel's calls in public, this final included.
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Prices quoted are from the settled trade log named above, re-verified on September 16, 2026; the match and title markets are finalized and no longer trade.
More on this: Gauff Vs Rybakina Odds: Buried At Match Point, Bought Back By Dinner · Sabalenka Vs Pegula Odds: The Last Set They Played Was 6-0. To Pegula · Zheng Vs Rybakina Odds: Three Straight First Sets, Two Losses Anyway
