Polymarket announced updates to its DeFi platform and the Market Integrity Rules for its CFTC-regulated U.S. exchange, further clarifying regulatory requirements for insider trading and market manipulation. The new rules specify three prohibited activities: trading on undisclosed information, building positions based on illegal information sources, and participation in trading by entities capable of influencing the outcome of events. The platform also explicitly prohibits fraudulent trading, wash trading, and price manipulation, and has launched a dedicated page to explain the rules and provide channels for reporting abnormal behavior. Furthermore, Polymarket stated that its DeFi platform uses on-chain transparency mechanisms and multi-layered monitoring systems for risk identification, while its U.S. platform combines technical monitoring with collaboration with industry regulators to investigate and punish violations.