Kalshi and Polymarket Set $8.56 Billion Two-Day Volume Record

Kalshi and Polymarket processed a combined $8.56 billion over two days, setting consecutive daily volume records as NFL and NCAA events accelerated activity on the platforms.

Their combined weekly volume reached $22.2 billion, also a record. The figures highlight the growing role of American football contracts in prediction markets alongside markets tied to Federal Reserve decisions, pop culture and other events.

The latest activity shows how strongly the current American football season is contributing to trading on the two platforms. NFL trading has also renewed scrutiny of how prediction-market contracts fit within sports-betting rules.

Earlier scrutiny has focused on trading patterns across both platforms, while Kalshi’s liquidity programs have also drawn attention. Kalshi rewards market makers for keeping orders available in its perpetual-futures markets, and says it uses controls to prevent self-trades and detect coordinated activity.

Polymarket says transactions on its international platform are publicly recorded onchain, with automated models, blockchain analysis and other surveillance systems used to examine trades and wallets. Its rules prohibit wash trading, spoofing, self-dealing and other manipulative conduct on its international and U.S. platforms.

Kalshi’s U.S. perpetual-futures products launched May 29, 2026, and have drawn more than 350,000 lifetime traders. These contracts have no expiration date and seek to follow the prices of their underlying assets.