Deputy Editor
A still-live prediction market on Polymarket appears to have spoiled the winner of the National Heads-Up Poker Championship, a long-celebrated event revived after more than a decade of dormancy. The tournament was pre-recorded but set to air this fall, with the results protected by a non-disclosure agreement in the meantime, as with other reality shows. However, one player’s odds of winning have been sent to nearly 100% by Polymarket traders, at least some of whom presumably have insider knowledge of the outcome.
Such leaks have become commonplace on Polymarket, which frames its “predictive power” as a positive. Security analysts agree with that assessment when it comes to predicting potentially dangerous world events. When it comes to spoiling people’s shows for them, however, we may start to see pushback.
Spoiler Alert: PokerScout wants to give our readers the choice to be spoiled or not. The identity of the presumed winner is disclosed at the bottom of the article, but only after a header clearly indicating “Spoilers Ahead.” You’re safe to read on, as long as you stop at that point if you don’t want the spoiler.
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Pre-Recorded Events Make Easy Targets for Insider Trading
Insider trading has been a recurring issue for this new form of event contract trading pioneered by the likes of Polymarket, Kalshi, and PredictIt. One would be hard-pressed to come up with an area more vulnerable to insider trading than pre-recorded reality TV, where outcomes are inevitably known to the cast and crew well ahead of the episodes’ airing dates.
Hence, the current, regrettable situation surrounding the National Heads-Up Poker Championship.
PokerGO brought back the event, which hadn’t run since 2013, along with presenting sponsor PokerStars. While the National Heads-Up Championship reboot played out Aug. 1-3, the planned airing of the $25,000, 64-player event was “fall 2025” on Peacock.
A PokerGO page says the on-demand streaming service will then air 10 episodes in 2026.
Several high-profile events recently made headlines when insiders seemingly profited from their knowledge.
- Bad Bunny was revealed as the Super Bowl halftime show headliner
- Someone trading on Polymarket knew Travis Kelce and Taylor Swift had gotten engaged before the Swift announced it
- A Polymarket trader caused odds on the Nobel Peace Prize winner to spike in the hours prior to the reveal
Is Insider Trading a Feature or a Bug?
Polymarket has publicly framed these instances of insider trading as a good thing. The company’s social media team has consistently marketed them as “liquidity revealing truth.”
Its response to the Nobel Peace Prize fiasco was to boast, rather than apologize:
“It has been revealed only five people at the Nobel Peace Prize foundation knew the winner before they were announced,” the company posted. “Everyone checking Polymarket knew.”
Another retweet of a sponsored account showed a market on President Donald Trump’s tariff policies with China. The market predicts just an 11% chance of the much-bandied about 100% tariffs going into effect. Sure enough, Trump seemingly softened his stance a day later, saying that “it will all be fine,” and, “the U.S.A. wants to help China.”
“Polymarket gives us answers before Wall Street even can,” the post boasted.
Those outside the company are not so sure that’s a good thing. One industry observer who has written somewhat extensively on the proliferation of prediction markets wrote:
Insider trading is a bug, not a feature, and should not be glorified in any form. In addition to being unethical (and illegal), it punishes the market makers and recreational participants that are the backbone of markets. Pls fix @mansourtarek_ @luanalopeslara @shayne_coplan
— Man of the Vig (@VigPolice) October 10, 2025
Insider Trading on Polymarket is Allowed … For Now
The words “insider trading” do not appear anywhere in Polymarket’s terms of service. It does prohibit “manipulation” and “front-running,” among other violations. Front-running is similar to but narrower than insider trading, referring to the exploitation of non-public knowledge of another party’s pending trades. So, trading based on knowing who won the Championship is okay, but trading based on knowing who’s about to buy shares in the winner might not be.
However, there’s an important factor to keep in mind: Polymarket isn’t yet regulated by the Commodity Futures Trading Commission (CFTC) in the U.S. It has received clearance to return to the U.S., but that’s still pending, and possibly delayed by the government shutdown.
The CFTC does have rules requiring its licensees to police “unfair trading practices.” That may explain why most of the discourse around insider trading linked above has centered around contracts on Polymarket rather than competitor Kalshi. Unlike Polymarket, Kalshi has a U.S. license and, until very recently, operated exclusively in the states.
As it moves to regulated operations in the US, Polymarket may have to change its policies to match Kalshi’s when it comes to insider trading.
Still, the idea that this will stop insider trading seems more like blind optimism than anything rooted in reality. With countless markets posted on these sites and plausible deniability presumably at the ready, policing these insider trades likely isn’t realistic. An exceptionally high-profile example could change that. But observers can expect insiders to continue profiting from some of these markets in the near future.
OK, enough preamble. Below, we’ve spoiled the result of the National Heads-Up Poker Championship. Do not read any further if you wish to conserve suspense around the outcome.
SPOILERS AHEAD: Who Won the Heads-Up Championship?
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According to the Polymarket odds movement, the answer appears to be Sam Soverel.
Polymarket opened trading on the outcome in early August, just after the event played out. By Aug. 6, just three days after it ended, the result had evidently leaked. Soverel got bet out to more than 95% probability that day, and he peaked at more than 99% in the following weeks.
Currently, Soverel’s odds have dropped a bit, but he’s still sitting north of 92% at the time of writing (Oct. 14).
The only other players above 1% are Brian Rast, Erik Seidel, and Sean Winter.
