Defending champion Carlos Alcaraz is Polymarket's clear favorite to win the 2026 US Open, last trading 56.5c bid 56c / ask 57c, as of 2026-09-07 12:48 UTC. That is up 9 points on the day and up 22 points since September 1, after he swept Tommy Paul 6-4, 6-3, 6-4 to reach the quarterfinals on September 6. He plays American Ben Shelton, trading 8.35c, on September 8. Alexander Zverev is the clear second favorite at 23.1c. The "2026 Men's US Open Winner" event has traded $1.13M over the past 24 hours on $1.10M of liquidity. Numbers below are from Gamma and the CLOB, fetched at that time.
01What happenedStraight sets past Paul, and the draw keeps thinning
Alcaraz beat 13th-seeded Tommy Paul 6-4, 6-3, 6-4 on September 6 to reach his fifth straight US Open quarterfinal, where he faces Ben Shelton, who dispatched Stefanos Tsitsipas 6-2, 6-3, 6-4 the same day. It sets up one of the tournament's most anticipated matches: the defending champion against a 26th-seeded American with a top-15 serve, in front of a home crowd. Alcaraz is chasing his third US Open title in four years and a second straight, and a win over Shelton would put him in the semifinals for the fourth consecutive year.
The rest of the draw has also been thinning in ways that favor the field's remaining favorites. This blog covered world No. 1 Jannik Sinner's August 21 US Open withdrawal with a knee injury, which first pushed Alcaraz and Zverev to the top of the ladder; since then, 9th seed Taylor Fritz lost a five-set upset to Francisco Cerundolo, and Daniil Medvedev fell to Frances Tiafoe in three tight sets, one of three American men - Tiafoe, Alex Michelsen, and Shelton - to reach the quarterfinals, the deepest US men's showing at a major since 1995.
02The chartA week of climbing, then a step on match day
Alcaraz's contract climbed steadily all week - 34.5c on September 1, grinding up through the low 40s by September 4-5 as he advanced through the early rounds without dropping a set - then took its clearest step around 20:00 UTC on September 6, from a 46.5c plateau to a 57.5-58.5c intraday high, once the straight-sets win over Paul was final. It has settled at 56.5c since, a 22-point week and a 9-point day. Zverev's contract, by contrast, spent the same week chopping in a tight 20-24c band with no comparable step - his own fourth-round win didn't move his price nearly as much, because the market had already priced him as the clear second favorite for days.
03The field nowAlcaraz clear, Zverev alone in second, a long American tail
2026 US OPEN WINNER (M) PRICE 24H
Carlos Alcaraz 56.5c +9.0c
Alexander Zverev 23.1c -1.4c
Ben Shelton 8.4c +0.9c
Frances Tiafoe 3.7c +1.5c
Learner Tien 3.6c -0.6c
Alex Michelsen 1.6c +0.6c
Jannik Sinner (withdrew Aug 21) 0.0c --
The 33.4-point gap between Alcaraz and Zverev is far wider than the 2.45c that separated them when this blog last checked the ladder on August 30, the day the main draw began. Shelton, Tiafoe, and Michelsen - the three Americans still alive - together price under 14c combined, reflecting that all three still have to get past a higher seed to reach the final. Sinner's contract, closed since his withdrawal, has printed a stray -35.45c "24h change" in Gamma's feed with zero matching volume; that figure is a stale artifact of a market with no live book, not a real move, and worth flagging as one of the reasons this blog treats a market's own `volume24hr` as the check on whether a price move is real.
04Reading the bookA cent-wide market with real size behind it
TOP OF BOOK, 2026-09-07 12:48 UTC
Alcaraz bid 0.56 x 10,874 ask 0.57 x 28,511
Zverev bid 0.23 x 145 ask 0.232 x 654
Alcaraz's book carries real depth on both sides of a 1c spread - almost 11,000 shares bid at 56c and over 28,000 offered at 57c - the kind of two-sided size that shows up when a lot of the market agrees roughly where the price belongs, not when one side is chasing the other. Zverev's book, by contrast, is thin: a few hundred shares on either side of the touch. That gap in depth, not just price, is part of why Alcaraz reads as the field's genuine favorite rather than merely the highest number on the ladder - Zverev's price could move further on comparatively little size.
05Watching the rest of the drawFour contenders, one screen
A tournament-winner event like this one is really twenty-two separate Yes/No contracts, one per contender, each closing independently the moment its own outcome is settled - Sinner's closed on August 21, and Fritz's and Medvedev's closed with their fourth-round losses this weekend, while Alcaraz's, Zverev's, Shelton's, Tiafoe's, and Michelsen's all keep trading into the quarterfinals. polymarket-tui lists an event's outcomes together with live price and 24-hour change, so a ladder like this one shows its shape - who is thinning out, who is climbing - at a glance instead of a lookup per player.
$ uv tool install polymarket-tui
$ polymarket-tui
No account is needed to browse markets, books, and charts. The install page has Homebrew and one-liner options.