Kalshi Reaches All-Time High $14.81B in April Volume as Prediction Market Sector Passes $150B Milestone

Key Highlights

• Combined lifetime trading volume for Kalshi and Polymarket surpassed $150 billion during April 2025
• Kalshi achieved an all-time monthly record of $14.81 billion in volume, marking a 13.3% increase from March
• Polymarket experienced a 14.8% decline to $9.01 billion, expanding Kalshi’s monthly advantage to $5.8 billion
• Active user count on Polymarket decreased from 733,000 in March to 643,000 in April
• Sports betting and parlay-style “Exotics” contracts represent approximately 85% of Kalshi’s trading activity

The prediction market industry reached a significant benchmark in April as Kalshi and Polymarket collectively surpassed $150 billion in all-time trading volume. This achievement occurred despite the sector experiencing its first month-over-month decline in trading activity following seven consecutive months of expansion.

Kalshi led the charge with an impressive $14.81 billion in notional trading volume throughout April. This represented a 13.3% jump compared to the platform’s March record of $13.07 billion.

The timing made this performance particularly noteworthy. Unlike previous months, April lacked major sporting tentpole events like the Super Bowl, March Madness finals, or NFL playoff games. Instead, the month featured the commencement of NBA and NHL playoffs, The Masters golf championship, and the opening weeks of Major League Baseball’s season.

The Masters tournament alone drove $545 million in notional volume on Kalshi — precisely matching the platform’s Super Bowl single-game volume of $545.1 million.

Meanwhile, Polymarket saw its trajectory reverse. The platform’s notional volume contracted 14.8%, declining from $10.57 billion in March to $9.01 billion in April. This downturn widened Kalshi’s monthly advantage over Polymarket to $5.8 billion, significantly larger than the $2.5 billion differential observed in March.

Sports Betting and Exotic Contracts Fuel Kalshi’s Momentum

Sports-related contracts dominated Kalshi’s activity, comprising 74.3% of weekly volume during the week ending April 20. When factoring in Exotics — the platform’s innovative parlay-style combination contracts — this proportion climbed to approximately 85%.

The Exotics category is experiencing rapid expansion. During the week of April 20, these contracts generated $412.5 million in volume, representing roughly 10.6% of Kalshi’s total weekly activity, up from 8.7% the previous week.

In terms of taker volume for April, Kalshi recorded $5.42 billion compared to Polymarket’s $1.99 billion. Kalshi also processed a higher transaction count — 94.4 million versus Polymarket’s 87.4 million — reversing a historical pattern where Polymarket had maintained the lead in transaction volume.

Polymarket’s Diversified Category Mix Shows Volatility

Polymarket operates with a distinctly different category distribution than Kalshi. During the week of April 20, sports markets led at 46%, while cryptocurrency-related markets captured 22% and political prediction markets contributed an additional 27%.

This diversified approach provides Polymarket with advantages during periods of heightened crypto market activity or significant political developments. However, when both sectors experience lulls — as occurred during portions of April — the platform lacks the concentrated sports betting volume that sustains Kalshi’s baseline activity.

Polymarket’s active trader population declined from approximately 733,000 in March to roughly 643,000 in April. This reduction indicates that some of March’s engagement was likely attributed to March Madness tournament excitement, with April figures reflecting more normalized user participation levels.

Regarding regulatory developments, Polymarket is reportedly pursuing entry into the U.S. market after acquiring a CFTC-licensed derivatives exchange. Kalshi secured funding in March at a $22 billion valuation. Polymarket is currently seeking investment at a reported $15 billion valuation.

Nine months prior, the prediction market sector processed approximately $2 billion in combined monthly volume. By April 2026, total monthly volume across both platforms reached roughly $28 billion.