July 21 — According to Bloomberg, as prediction markets like Polymarket and Kalshi expand, the issue of betting using non-public information or information advantages is facing more scrutiny. Bloomberg Businessweek analyzed approximately 34,000 potential insider trades flagged by Polysights between August 2025 and June 2026; these trades are characterized by new accounts, low-probability entries, large bets, or high trading concentration, but this alone does not confirm that traders violated rules. Data shows that from January 1 to June 30 this year, the amount of suspicious transactions flagged on Polymarket was about $200 million, with geopolitical and war-related markets driving notable growth in abnormal trading volumes. Profits from potential insider trading are highly concentrated, with the top 1% of accounts in profitable wallets capturing more than half of the gains, and 57% of relevant wallets were created less than 24 hours before trading. Some traders are using multiple related wallets and splitting orders to reduce the likelihood of detection. For example, 38 linked addresses placed bets in 90 geopolitical markets related to Iran and Venezuela, achieving a 98% win rate and collectively profiting $1.6 million, withdrawing funds through the same Coinbase deposit address. Polymarket stated that it monitors insider trading and other illegal activities, and has so far referred nearly 100 wallets to law enforcement agencies. Kalshi has also strengthened identity and employment information reviews and restricted participation in relevant markets by political candidates, athletes, and others who may influence outcomes.