The women's singles bracket hit reset on itself on the first day of the tournament.
Second-best favorite Simona Halep had pre-tournament odds as short as +700 to win her first ever US Open. Those were only bested by world No. 1 Iga Swiatek, who had roughly +450 odds.
But, as a -1600 favorite against Ukrainian Daria Snigur, Halep spiraled into a three set loss that reoriented odds across the markets.
The Romanian international had received 6.9% of all futures tickets and 4.6% of all the betting handle to win the tournament.
Her loss didn't affect Serena Williams' odds, though. Serena's route to the final would have encompassed Halep in the semifinals only. The marketplace doesn't think she'll get that far, anyway.
Serena is still tied for 17th-best in the marketplace at +3300 to win the tournament on account of lackluster recent performances. Williams is also just a few months removed from returning to play after a torn hamstring suffered at 2021's Wimbledon kept her out of tennis for about a year.
The six-time US Open champion has said that she'll retire after this US Open.
Meanwhile, the odds for Swiatek have shortened mildly from +450 to +350. The Polish international would have had to face Halep in the final.
American teenager Coco Gauff's odds received the biggest buoy as a result of Halep's loss.
Gauff had been roughly +1600 across the market to win the US Open — now, those odds are about +1000. Gauff would have had to face Halep in the fourth round. The 30-year-old Halep is 4-0 against the 18-year-old Gauff.
Gauff replaced Halep as the second-best favorite across the market.
Caroline Garcia also received a jump in odds, boosting her to third-best in the overall odds at +1200.
