The prediction market boom continues to accelerate, with Dune Analytics reporting that seven major platforms collectively recorded $25.7 billion in notional volume during March 2026. This marks the second-highest monthly total on record, trailing only January's record of $26.75 billion. The cumulative volume since January 1, 2024 has now reached $162.64 billion.
Polymarket and Kalshi Dominate the Landscape
The data, compiled by @datadashboards on Dune.com, reveals a highly concentrated market. Kalshi led with $13 billion in March volume, followed closely by Polymarket at $10 billion. Their combined share accounts for nearly 90% of the total. Polymarket’s volume is primarily driven by political events, with crypto, sports, and global events also contributing significantly. Kalshi, meanwhile, sees robust activity across economics, financials, and politics, while branching into niche verticals such as climate, weather, and transportation.
Transaction Activity and Open Interest
March witnessed a sharp increase in transaction count, reaching approximately 207 million transactions across all tracked platforms — up from 155 million in February. Polymarket handled 115 million of those trades, while Kalshi processed 88 million. The remaining platforms — Crypto.com, Opinion, Limitless, Predict.fun, and Overtime.io — lagged far behind.
Open interest across prediction markets currently stands at about $939.86 million, with Kalshi holding $487.21 million and Polymarket $422.09 million. This means the two giants control over 90% of all open positions. Smaller platforms like Predict.fun ($19.51M) and Opinion ($10.38M) trail distantly, while Limitless ($666,520) and others ($3,760) are negligible, highlighting a starkly top-heavy market structure.
Regulatory Headwinds and Resilience
Despite these impressive numbers, prediction markets continue to face scrutiny. Controversies surrounding markets tied to the U.S.-Iran conflict have drawn criticism, and Democratic lawmakers have advanced legislation aimed at tightening oversight. Most recently, California Governor Gavin Newsom signed an executive order barring gubernatorial appointees from using insider information to place bets on prediction platforms. The two dominant platforms also navigate conflicting state-level rules and federal guidance from the Commodity Futures Trading Commission (CFTC).
Nevertheless, both volume and open interest have continued to climb, suggesting that prediction markets have carved out a durable role in the financial ecosystem. How long this momentum can persist amid regulatory uncertainty remains to be seen, but for now, the industry shows no signs of slowing down.