Key Takeaways:
Kalshi posted $5.42B in April 2026 taker volume, surpassing Polymarket’s $1.99B for the first time. Polymarket collected $29.22M in April fees despite trailing Kalshi in volume, signaling higher-value contracts. Prediction market open interest hit $1.11B on May 1, 2026, with Kalshi and Polymarket holding 98% of it. Kalshi Holds $630M in Open Interest as Sector-Wide OI Tops $1.1B at the Start of MayOpen interest across the sector stood at $1.11 billion as of May 1, 2026. Kalshi held $630.7 million of that total while Polymarket carried $449.9 million. Predict.fun, Opinion, and Limitless each held well under $15 million in open positions.
Sector RevenueMonthly fees generated across the sector reached $31.15 million in April. Polymarket collected $29.22 million of that total, a figure based on resolution price and mergeable amounts. Limitless followed at $1.51 million, with Predict and Opinion generating $260,000 and $154,000 respectively.
