Polymarket’s monthly trading volume declined 8.9% in April to $10.2 billion, marking its first month-over-month drop since last August. In contrast, rival Kalshi’s April volume increased 13% to $14.8 billion. Combined with broader market activity, total prediction market volume reached about $29.8 billion in April. The figures indicate a split in momentum across prediction market platforms at a time of tighter U.S. regulatory scrutiny, a factor that can affect platform access, product design, and user participation in event-based trading markets.