New York City Council Speaker Julie Menin has launched a sweeping investigation into four prediction markets operating in the city, targeting Polymarket, Kalshi, Coinbase, and Gemini for alleged deceptive marketing practices and potential violations of consumer protection laws.

The investigation, announced through letters sent on Aug. 11, specifically scrutinizes how these companies market their platforms and whether their promotional efforts improperly target minors. Menin directly addressed Shayne Coplan, founder and CEO of Polymarket, requesting details about promotional videos that allegedly depicted fake trades and promoted insider trading on social media.

The probe adds to the growing state-by-state legal battles over prediction-market regulation. A June analysis by the Wall Street Journal reviewed over 1,100 videos created by Polymarket influencers and found that 70% featured dummy sites used to stage fake trades, raising further concerns about misleading marketing tactics in the rapidly expanding prediction-market industry.