The predictions derived from Polymarket’s betting action—Coplan has called the operation a “global truth machine”—are now cropping up everywhere. Analysts and national news outlets cite them regularly. Viewers of the Golden Globes saw them on their TV screens. Google, X, the National Hockey League and Dow Jones, the publisher of The Wall Street Journal, have all struck data partnerships with Polymarket. Yet for all its mainstream success, Polymarket hasn’t managed to stamp out controversy tied to its freewheeling markets, most of which remain unregulated.