Kalshi and Polymarket Are Spoiling Reality TV Shows — and Studios Don’t Know What to Do About It
The winner of CBS’ “Survivor 50” was announced live on air on May 20.
But traders on prediction market platforms Kalshi and Polymarket — and “Survivor” fans exposed to reports of the fluctuating odds — saw Aubry Bracco’s payday coming before the season even began.
When a “Survivor 50” market opened on Kalshi six weeks before the Feb. 25 season premiere, preliminary trades forecast Bracco to have a 61% chance of winning — nearly double the odds of her next closest competitor. By Jan. 28, she had jumped to 83%. And on Feb. 28, just days after the premiere and before Bracco had accumulated much screen time, a user bet $45,500 she would win the season (which later earned them a profit of $4,500). By market’s close on the day of the finale, a staggering $32.7 million in wagers had lifted her odds to 97%. (On Polymarket, “Survivor 50” predictions only reached a trade volume of $1.9 million, but the odds followed a similar trajectory.)
For anyone following along, Bracco seemed all but certain to be crowned the Sole Survivor. Minutes before the finale, Kalshi goaded in a push notification: “Is the island already decided?”
Pretaped reality TV shows are facing an unforeseen problem: Prediction markets are spoiling their endings. It’s not just “Survivor”: Kalshi users correctly predicted Galaxy Girl, at 91% odds, would win this season’s “Masked Singer” three months before Ashlee Simpson removed her space-themed costume in the finale. The site similarly spoiled the winner of “Next Level Chef” in February, though the season didn’t conclude until May 21. And Doug Mason, a contestant on the ill-fated Season 22 of “The Bachelorette,” peaked at 89.5% on Polymarket and 93% on Kalshi before ABC canceled the premiere. The season may never air, but to find out who received the final rose, just follow the money.
By way of blogs like RealitySteve and Reddit pages like SpoiledSurvivor, there’s a long history of unscripted shows being spoiled on the internet. Networks tend to assume these leaks spring from cast members. But “Survivor 50” contestants were sent home in July 2025 without being told the winner; they had to wait until the live finale to see host Jeff Probst read the votes onstage. That means only a select number of “Survivor” staffers had knowledge of Bracco’s victory — forcing CBS, a source says, to reckon with the fact that any leak would have had to come from production.
Insider trading is banned on both Kalshi and Polymarket, and Kalshi’s head of communications, Elisabeth Diana, says the platform uses AI-powered third-party surveillance to detect suspicious transactions. The company has repeatedly assured that it’s investigating its “Survivor” market. (Reps for Polymarket did not respond to a request for comment.)
“No traders with large positions seem to have a relationship to the show or to the network,” Kalshi’s head of enforcement, Robert DeNault, wrote on X following the finale.
Regarding the depth of their investigations, Diana says, “We don’t just look at the people in the household of a person trading. We can also see from their social activity, what they’re doing on the site, who they’re connected to.” If an AI-flagged trade is deemed anomalous, Kalshi reps interview the trader to assess wrongdoing. The company has publicly cracked down on five offenders, including a video editor who worked for MrBeast.
If no insider trading is occurring in these reality TV markets, as Kalshi claims, how have users’ predictions become so accurate? If you ask the company, it’s because traders consult spoilers that are already circulating online. Whether those spoilers originated with insiders is irrelevant to Kalshi brass as long as the traders themselves haven’t broken the law.
“RealitySteve obviously has people talking to him and maybe leaking information, which isn’t good, but he puts it online,” Diana says. Kalshi’s investigations have largely found that traders on the “Survivor” market were following intel from a Reddit user known as “Lifetimerobot,” who has a strong track record for accurately spoiling the show. As DeNault wrote, “Public rumors don’t equal insider information.”
Update: we continue to investigate insider trading in Survivor markets, but the below still holds true: so far, no traders with large positions seem to have a relationship to the show or to the network. Thousands of traders took early positions consistent with the outcome, likely… https://t.co/yF77b2VaAI
Still, those rumors used to be flagged with spoiler warnings, making it easy for casual viewers to avoid seeing them. Now, betting odds on Kalshi and Polymarket proliferate on social media, and the amount of money behind the predictions make them hard to dismiss.
“In the past, there was a plausible deniability to it. If someone’s telling you Aubry wins, you could be like, ‘You don’t know what you’re talking about,'” says one Kalshi trader who earned about $500 trading on Bracco. “Now, people are putting bets of thousands of dollars on it, and you take it more seriously. It has removed that layer of being able to cover your eyes and pretend.”
That new certainty poses a major headache for studios. One industry insider takes an optimistic view, suggesting that multimillion-dollar prediction markets could help drum up excitement and ratings. But many are concerned that spoilers remove suspense and can turn off viewers entirely.
A source at CBS parent company Paramount says there have been executive-level conversations about insider trading on prediction markets. The problem, the source says, is that it’s almost impossible for studios to put a stop to it. While legal and compliance departments at corporations can enforce strict policies with respect to the stock exchange, massive amounts of money, time and corporate infrastructure would be required to effectively extend insider trading governance and compliance technology to prediction markets.
“The tools aren’t there yet,” the Paramount source says. “The markets are outrunning regulation.”
Networks could explicitly prohibit engagement with prediction markets in NDAs signed by production staffers. But that would be difficult to enforce given that most reality TV crew members are independent contractors, not salaried employees being monitored by compliance technology. Failing that, studios could prevent leaks by restructuring their shows and removing pre-taped elements altogether, but that could be an even bigger logistical nightmare.
Legal battles over prediction markets are ongoing at the state level — Minnesota is the first state set to ban them — but the federal government has yet to address insider trading on the platforms in any meaningful way.
So the trades are not slowing down: The Kalshi market for “Survivor” Season 49, which correctly predicted Savannah Louie’s win, brought in just $2.4 million; Season 50 drove a volume increase of 1,284%.
The Paramount source proposes one potential solution: Studios could form partnerships with Kalshi or Polymarket, perhaps collaborating on certain types of markets related to their shows and advertising them on air — in exchange for shutting down other, spoilery ones.
But prediction market platforms wouldn’t necessarily be willing to make such deals. “We would not be able to compromise on the experience for traders,” Diana says. “Traders are the people keeping the site going, so we’ve got to always prioritize their needs over any partners’ needs.”
So when it comes to stopping leaks, the Paramount source says studios are on their own: “The only viable path is for corporations to monitor themselves.”
Until then, to paraphrase “Survivor” icon Sue Hawk, “this island is full of snakes and rats.”
But traders on prediction market platforms Kalshi and Polymarket — and “Survivor” fans exposed to reports of the fluctuating odds — saw Aubry Bracco’s payday coming before the season even began.
When a “Survivor 50” market opened on Kalshi six weeks before the Feb. 25 season premiere, preliminary trades forecast Bracco to have a 61% chance of winning — nearly double the odds of her next closest competitor. By Jan. 28, she had jumped to 83%. And on Feb. 28, just days after the premiere and before Bracco had accumulated much screen time, a user bet $45,500 she would win the season (which later earned them a profit of $4,500). By market’s close on the day of the finale, a staggering $32.7 million in wagers had lifted her odds to 97%. (On Polymarket, “Survivor 50” predictions only reached a trade volume of $1.9 million, but the odds followed a similar trajectory.)
For anyone following along, Bracco seemed all but certain to be crowned the Sole Survivor. Minutes before the finale, Kalshi goaded in a push notification: “Is the island already decided?”
Pretaped reality TV shows are facing an unforeseen problem: Prediction markets are spoiling their endings. It’s not just “Survivor”: Kalshi users correctly predicted Galaxy Girl, at 91% odds, would win this season’s “Masked Singer” three months before Ashlee Simpson removed her space-themed costume in the finale. The site similarly spoiled the winner of “Next Level Chef” in February, though the season didn’t conclude until May 21. And Doug Mason, a contestant on the ill-fated Season 22 of “The Bachelorette,” peaked at 89.5% on Polymarket and 93% on Kalshi before ABC canceled the premiere. The season may never air, but to find out who received the final rose, just follow the money.
By way of blogs like RealitySteve and Reddit pages like SpoiledSurvivor, there’s a long history of unscripted shows being spoiled on the internet. Networks tend to assume these leaks spring from cast members. But “Survivor 50” contestants were sent home in July 2025 without being told the winner; they had to wait until the live finale to see host Jeff Probst read the votes onstage. That means only a select number of “Survivor” staffers had knowledge of Bracco’s victory — forcing CBS, a source says, to reckon with the fact that any leak would have had to come from production.
Insider trading is banned on both Kalshi and Polymarket, and Kalshi’s head of communications, Elisabeth Diana, says the platform uses AI-powered third-party surveillance to detect suspicious transactions. The company has repeatedly assured that it’s investigating its “Survivor” market. (Reps for Polymarket did not respond to a request for comment.)
“No traders with large positions seem to have a relationship to the show or to the network,” Kalshi’s head of enforcement, Robert DeNault, wrote on X following the finale.
Regarding the depth of their investigations, Diana says, “We don’t just look at the people in the household of a person trading. We can also see from their social activity, what they’re doing on the site, who they’re connected to.” If an AI-flagged trade is deemed anomalous, Kalshi reps interview the trader to assess wrongdoing. The company has publicly cracked down on five offenders, including a video editor who worked for MrBeast.
If no insider trading is occurring in these reality TV markets, as Kalshi claims, how have users’ predictions become so accurate? If you ask the company, it’s because traders consult spoilers that are already circulating online. Whether those spoilers originated with insiders is irrelevant to Kalshi brass as long as the traders themselves haven’t broken the law.
“RealitySteve obviously has people talking to him and maybe leaking information, which isn’t good, but he puts it online,” Diana says. Kalshi’s investigations have largely found that traders on the “Survivor” market were following intel from a Reddit user known as “Lifetimerobot,” who has a strong track record for accurately spoiling the show. As DeNault wrote, “Public rumors don’t equal insider information.”
Update: we continue to investigate insider trading in Survivor markets, but the below still holds true: so far, no traders with large positions seem to have a relationship to the show or to the network. Thousands of traders took early positions consistent with the outcome, likely… https://t.co/yF77b2VaAI
Still, those rumors used to be flagged with spoiler warnings, making it easy for casual viewers to avoid seeing them. Now, betting odds on Kalshi and Polymarket proliferate on social media, and the amount of money behind the predictions make them hard to dismiss.
“In the past, there was a plausible deniability to it. If someone’s telling you Aubry wins, you could be like, ‘You don’t know what you’re talking about,'” says one Kalshi trader who earned about $500 trading on Bracco. “Now, people are putting bets of thousands of dollars on it, and you take it more seriously. It has removed that layer of being able to cover your eyes and pretend.”
That new certainty poses a major headache for studios. One industry insider takes an optimistic view, suggesting that multimillion-dollar prediction markets could help drum up excitement and ratings. But many are concerned that spoilers remove suspense and can turn off viewers entirely.
A source at CBS parent company Paramount says there have been executive-level conversations about insider trading on prediction markets. The problem, the source says, is that it’s almost impossible for studios to put a stop to it. While legal and compliance departments at corporations can enforce strict policies with respect to the stock exchange, massive amounts of money, time and corporate infrastructure would be required to effectively extend insider trading governance and compliance technology to prediction markets.
“The tools aren’t there yet,” the Paramount source says. “The markets are outrunning regulation.”
Networks could explicitly prohibit engagement with prediction markets in NDAs signed by production staffers. But that would be difficult to enforce given that most reality TV crew members are independent contractors, not salaried employees being monitored by compliance technology. Failing that, studios could prevent leaks by restructuring their shows and removing pre-taped elements altogether, but that could be an even bigger logistical nightmare.
Legal battles over prediction markets are ongoing at the state level — Minnesota is the first state set to ban them — but the federal government has yet to address insider trading on the platforms in any meaningful way.
So the trades are not slowing down: The Kalshi market for “Survivor” Season 49, which correctly predicted Savannah Louie’s win, brought in just $2.4 million; Season 50 drove a volume increase of 1,284%.
The Paramount source proposes one potential solution: Studios could form partnerships with Kalshi or Polymarket, perhaps collaborating on certain types of markets related to their shows and advertising them on air — in exchange for shutting down other, spoilery ones.
But prediction market platforms wouldn’t necessarily be willing to make such deals. “We would not be able to compromise on the experience for traders,” Diana says. “Traders are the people keeping the site going, so we’ve got to always prioritize their needs over any partners’ needs.”
So when it comes to stopping leaks, the Paramount source says studios are on their own: “The only viable path is for corporations to monitor themselves.”
Until then, to paraphrase “Survivor” icon Sue Hawk, “this island is full of snakes and rats.”