Prediction market platforms Kalshi and Polymarket are seeing a major rise in suspicious trading activity as the industry continues to grow at a rapid pace. According to Reuters, Kalshi has already investigated more than 400 suspicious trades in 2026. This may be cause for alarm. We are less than half way through the year, yet the total is already more than double the number reviewed during all of 2025.
Polymarket has also reportedly experienced a significant increase in flagged trading activity this year.
Trading Volumes Continue Exploding
The rise in suspicious bets comes as prediction markets continue posting massive growth in trading volume. Kalshi’s annualized trading volume has climbed to roughly $178 billion. Polymarket’s monthly trading volume reached approximately $10.3 billion during April 2026.
The success is helping to push these prediction markets further into the mainstream financial conversation.
Platforms Increase Monitoring Efforts
Both companies are now increasing compliance efforts and strengthening internal monitoring systems. The goal is to identify suspicious patterns and crack down on possible insider trading. Some cases have reportedly been referred to the Commodity Futures Trading Commission.
The companies are also introducing additional safeguards and clearer policies surrounding trading on non-public information.
Prediction Markets Are Growing
Prediction markets allow users to trade contracts tied to real-world outcomes. Markets include politics, sports, entertainment, weather and more. Supporters believe prediction markets can act as powerful forecasting tools that reflect public expectations. However, critics worry that people with access to private information could gain unfair advantages.
Industry Faces Growing Scrutiny
The continued rise in suspicious trading activity is drawing more attention from lawmakers and regulators. Platforms face mounting pressure to prove their markets can remain fair and transparent.
The bottom line is clear: Prediction markets are expanding quickly, but long-term growth may depend on how effectively platforms protect trust and market integrity.
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