Serghei Spivac vs Vitor Petrino Prediction Market Odds, August 22, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
Spivac | — | O 0.5 — | 0%0% | — |
Petrino | — | U 0.5 — | 100%100% | 100% Kalshi |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
Serghei Spivac | — | O 0.5 — | 0%0% | — |
Vitor Petrino | — | U 0.5 — | 100%100% | 100% Kalshi |
Vitor Petrino is the 59c favorite over Serghei Spivac and the two exchanges agree to the cent on the favorite, with Kalshi and Polymarket both at 59c on Petrino and 43c and 42c respectively on Spivac. The board has taken $149.2K in lifetime cross-platform volume, and 91% of it sits on Kalshi. Petrino (14-2) has won three straight since moving to heavyweight, Spivac (18-6) is 2-3 in his last five, and the fight is the three-round heavyweight co-main event at UFC Fight Night: Hernandez vs. Rodrigues in Sacramento. The live board above carries the current prices.
Vitor Petrino is the 59c favorite over Serghei Spivac on both Kalshi and Polymarket, which is the single most interesting thing about this board. Two exchanges with separate order books, separate user bases and $149.2K of combined lifetime volume have landed on the same number for the favorite. The fight is the second-to-last bout at UFC Fight Night: Hernandez vs. Rodrigues at Golden 1 Center in Sacramento, California, scheduled for three rounds at heavyweight per ESPN's fight card, and it settles on the announced winner the same night.
Spivac vs Petrino Market Context
ESPN lists Spivac at 18-6 and Petrino at 14-2 going into this one, and the two records point in opposite directions. Petrino is 3-0 since moving up to heavyweight: a rear naked choke over Austen Lane in July 2025, a strikes stoppage of Thomas Petersen in October 2025, and a unanimous decision over Steven Asplund on March 14, 2026. Those three wins followed the two losses that ended his light heavyweight run, a guillotine to Anthony Smith in May 2024 and a strikes loss to Dustin Jacoby in December 2024. The 59c price is the market reading a 28-year-old who fixed his career by changing weight classes. ESPN lists Petrino at 28 years old, 6 feet 2 inches and 246 pounds, against Spivac at 31, 6 feet 3 inches and 257 pounds, so the size edge on fight night belongs to the underdog.
Spivac is the harder read. He is 2-3 across his last five per ESPN's event log: a unanimous decision win over Ante Delija in February 2026, losses to Waldo Cortes-Acosta in June 2025 and Jailton Almeida by strikes in January 2025, an armbar finish of Marcin Tybura in August 2024, and a strikes loss to Ciryl Gane in September 2023. The pattern is legible. When Spivac gets the fight to the mat he finishes it, and the Tybura armbar is the cleanest recent evidence of that. When he does not, he gets hurt on the feet. At 42c to 43c the market is paying for the grappling path and discounting everything else.
On the moneyline there is no cross-platform value here, and it is worth saying that plainly rather than manufacturing one. Kalshi prices the pair 59c and 43c for a 102c book, which is the ordinary exchange vig on a two-way market. Polymarket prices it 59c and 42c for a 101c book. The one cent of separation on the Spivac side is rounding, not an edge. Where the two venues genuinely diverge is depth: Kalshi has taken $69.6K on the Petrino contract and $66.3K on the Spivac contract against $12.1K on the Polymarket event, so roughly 91% of the price discovery on this fight is happening on Kalshi.
The board carries about eleven hours of snapshot captures, running to 11:21 UTC on August 22, and it has held rather than moved. Petrino ticked from 58c to 59c on Kalshi across 70 captures and never left 59c on Polymarket across 39. Spivac ran the mirror of that, 42c to 43c on Kalshi and flat at 42c on Polymarket. Scope any movement read to that window: this board has no deeper snapshot history yet, so the honest statement is that the price has been stable for the captures we hold, not that it has been stable since it opened.
The method board is Polymarket-only and thin, which changes how much weight it can carry. Fight to Go the Distance is the deepest of them at 40c on $1.1K of lifetime volume. Over 1.5 rounds sits at 65c and over 2.5 rounds at 48c, a ladder that is internally consistent with the 40c distance price. On method, Petrino by KO or TKO is 30c while Spivac by KO or TKO is 12c, so the market is assigning the striking finish equity almost entirely to Petrino, which fits a fighter whose last three wins include a strikes stoppage and a submission. Those two method contracts have moved under $40 between them in their lifetime, so treat them as indications of where the price would sit rather than as a book you can size into. The Nzechukwu vs Gaziev heavyweight board on the same card gives a useful comparison point for how this card's heavyweight bouts are being priced.
When the Spivac vs Petrino Market Resolves
The Spivac vs Petrino market resolves on August 22, 2026, to the fighter whose hand is raised when the bout is decided, by knockout, technical knockout, submission, or judges' decision across the scheduled three rounds. The main card is scheduled for 8:00 PM ET on Paramount+ per ESPN, and this bout is the last one before the five-round main event between Anthony Hernandez and Gregory Rodrigues, so it lands late in the broadcast. Kalshi runs two separate contracts, one per fighter, each paying $1 per share to the winner and $0 to the loser. Polymarket settles the shared event plus its round and method contracts off the same official result. A draw, a no contest, or a cancellation is handled by each platform's own void and refund rules, which differ between the two, so read the contract terms on the venue you trade before the card starts.
Key Spivac vs Petrino Catalysts
- Petrino's heavyweight run: three straight wins at the new weight after going 0-2 to close his light heavyweight run, which is what the 59c price is buying.
- Spivac's grappling path: his armbar finish of Marcin Tybura in August 2024 is the clearest recent evidence for the 42c to 43c side, and his losses to Ciryl Gane and Jailton Almeida both came by strikes.
- Cross-platform agreement: Kalshi and Polymarket both at 59c on Petrino leaves no moneyline value between venues, so any edge here has to come from the method or round board.
- Thin method book: Petrino by KO or TKO at 30c versus Spivac by KO or TKO at 12c is priced on under $40 of combined lifetime volume and will reprice fast if either side takes real size.
- Distance pricing: Fight to Go the Distance at 40c on $1.1K is the deepest prop on the board and the one most likely to lead the moneyline if the market changes its mind on finish probability.
- Card position: the co-main slot puts this bout late on a Paramount+ main card, so any late scratch or weight-miss news on the card ahead of it moves this board's timing, not its price.
Related Spivac vs Petrino Markets
The Hernandez vs Rodrigues main event is the deepest board on the card at $465.1K in lifetime volume and follows this fight directly. The Dolidze vs de Ridder light heavyweight board and the Mederos vs Jones lightweight board round out the main card above this bout. For every fight on this card and the rest of the promotion's schedule, the UFC prediction market hub carries the full board, and the sports markets index covers the cross-platform boards in every other league.
Resolution Criteria
Resolves on August 22, 2026, to the fighter declared the winner of the Serghei Spivac vs Vitor Petrino heavyweight bout at UFC Fight Night: Hernandez vs. Rodrigues at Golden 1 Center in Sacramento, California, by knockout, technical knockout, submission, or judges' decision over the scheduled three rounds. Kalshi lists two separate contracts, one per fighter, each paying $1 per share if that fighter wins and $0 otherwise. Polymarket settles the shared event market plus its round-total and method-of-victory contracts off the same official result announced in the cage. If the bout is canceled, postponed, ruled a draw, or overturned to a no contest, each platform applies its own void and refund rules, which are not identical, so the contract terms on the venue where the position is held govern.
Key Factors
- Petrino 14-2 and 3-0 since moving to heavyweight, after 0-2 to close his light heavyweight run
- Spivac 18-6 and 2-3 in his last five, with an armbar finish of Marcin Tybura as the grappling evidence
- Kalshi and Polymarket both at 59c on Petrino, so there is no moneyline value between the two venues
- Petrino by KO or TKO at 30c versus Spivac by KO or TKO at 12c on under $40 of combined lifetime volume
- Fight to Go the Distance at 40c on $1.1K, the deepest prop on an otherwise thin Polymarket method board
- Co-main slot on a Paramount+ main card scheduled for 8:00 PM ET, directly before the five-round main event
What are the current Spivac vs Petrino odds?
As of August 22, 2026, Vitor Petrino is the 59c favorite on both Kalshi and Polymarket, with Serghei Spivac at 43c on Kalshi and 42c on Polymarket. That is an implied win probability of roughly 59% for Petrino before accounting for the exchange vig.
Where can I trade the Spivac vs Petrino market?
Both Kalshi and Polymarket list the fight. Kalshi runs two separate per-fighter contracts and holds about 91% of the $149.2K in lifetime volume on this board. Polymarket carries the moneyline plus round-total and method-of-victory contracts that Kalshi does not list.
Who is favored in Spivac vs Petrino?
Vitor Petrino, at a 59c consensus price across the two platforms. He is 14-2 and has won three straight since moving to heavyweight, most recently a unanimous decision over Steven Asplund on March 14, 2026.
When does the Spivac vs Petrino market resolve?
On August 22, 2026, when the bout is decided. It is the heavyweight co-main event at UFC Fight Night: Hernandez vs. Rodrigues in Sacramento, on a main card scheduled to start at 8:00 PM ET on Paramount+, so it goes off late in the broadcast.
What do the round and method markets say about Spivac vs Petrino?
Polymarket prices Fight to Go the Distance at 40c, over 1.5 rounds at 65c and over 2.5 rounds at 48c. On method, Petrino by KO or TKO is 30c against Spivac by KO or TKO at 12c, though those two contracts carry under $40 of combined lifetime volume.
What should I watch before Spivac vs Petrino resolves?
Whether the 59c line holds through the day. The board has been stable at 58c to 59c on Petrino across roughly eleven hours of captures, so any move off that number before the 8:00 PM ET main card would be the first real signal this market has produced.