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- Kalshi and Polymarket are facing intensified mainstream scrutiny after a comprehensive Bradenton Herald report highlighted growing concerns over market integrity, celebrity-driven marketing, and the platforms’ heavy reliance on financially anxious younger demographics.
- Building on ongoing industry controversies, the report cited new research estimating that 25% of Polymarket‘s historical volume is wash trading and revealed that up to 90% of Kalshi‘s bets are sports-related—allowing the platform to bypass state gaming taxes and lower the legal gambling age to 18 by operating as a financial exchange. The critique also underscored severe insider-trading vulnerabilities, noting that former U.S. Rep. George Santos was quietly issued a lifetime ban from Kalshi after wagering on his own State of the Union attendance.
Prediction markets including Kalshi and Polymarket are drawing renewed scrutiny after a Bradenton Herald report tied their rapid growth to financially anxious younger users and raised new questions about trading concentration, market integrity, and sports-betting-style access.
The story matters for gambling and betting audiences because the platforms increasingly overlap with regulated wagering while arguing they should be treated as financial exchanges instead of traditional gambling products. That distinction affects taxes, age access, and where the products can operate.
In its report, the Herald said combined trading volume on the two platforms reached $24.2 billion in April 2026. It also cited a Wall Street Journal analysis that found 67% of profits on Polymarket went to 0.1% of accounts.
A Kalshi spokeswoman, according to the article, said nearly three users lose money for every one user who profits on the platform.
Celebrity marketing and younger users in focus
The report said both companies have leaned on celebrity-backed promotion. Kalshi ads have featured Timothée Chalamet, Giannis Antetokounmpo, and José Mourinho, while Polymarket produced an ad featuring more than a dozen celebrities, including LeBron James, Spike Lee, and Eli Manning.
The Herald also cited Northwestern Mutual’s 2026 Planning & Progress Study, which found 32% of Gen Z and 24% of millennials are invested in or considering prediction markets or sports betting. In the same study, 80% of Gen Z respondents interested in high-risk investments said they felt financially behind.
The article further reported that Kalshi has avoided state gaming taxes by maintaining it is a financial exchange rather than a sports-betting operator. According to the report, that approach has effectively lowered access from 21 to 18 and opened the door in states where sports betting is otherwise illegal. The article said sports account for about 80% to 90% of all bets placed on Kalshi.
Integrity concerns add to regulatory questions
Beyond marketing and access, the report pointed to market-integrity concerns on both platforms. A Columbia University study estimated about 25% of Polymarket’s historical trading volume was likely wash trading.
The Herald also cited a case in which George Santos received a lifetime ban from Kalshi after betting that he would not attend the State of the Union and then not attending. In a separate case, a U.S. Army Special Forces soldier has been charged with using classified information about a mission to capture Nicolás Maduro to win more than $400,000 on Polymarket. The soldier has pleaded not guilty.
The article noted that prediction markets can still have legitimate financial uses. It cited a paper by Federal Reserve Board economists finding that Kalshi forecasts for interest rates and inflation can outperform professional forecasters.
What comes next is still unclear. The source report raised open questions about which regulators may act, how sports and non-sports activity breaks down over time, and whether additional oversight will follow as prediction markets keep expanding in the U.S.
Source: As reported by Mark Butler.
