Key facts
- The Washington Post analysis said nearly $1.9 billion in election contracts had traded on Kalshi and Polymarket as of November 2, 2026.
- Kalshi gave Democrats a 93% chance of taking the House and 75% of the Senate; Polymarket priced 94.5% and 75.5%.
- Defend American Jobs, part of the Fairshake super PAC network, allocated 54% of its total expenses to the Ohio Senate race.
- The group spent $36.9 million supporting Senator Jon Husted and $19.7 million opposing Democrat Sherrod Brown, per its official website.
- Kalshi gave Democrat Mary Peltola a 71% chance of defeating Republican Senator Dan Sullivan in Alaska, where a New York Times/Siena poll had her ahead 48% to 46%.
- The Digital Freedom Fund, backed by Gemini co-founders Cameron and Tyler Winklevoss, spent more than $81,000 supporting Ken Paxton in Texas.
Prediction market traders priced a Democratic sweep of Congress at 75% on Kalshi and 75.5% on Polymarket as of 4:30 p.m. UTC on November 3, 2026, the day of the US midterm elections. An analysis by The Washington Post said nearly $1.9 billion in election-related contracts had traded on the two platforms as of the day before, which the analysis described as record activity for a midterm cycle.
On individual chambers, Kalshi traders gave Democrats a 93% chance of taking the House and a 75% chance of winning the Senate, while Polymarket priced those outcomes at 94.5% and 75.5%. The vote came nine days after prediction markets failed to anticipate the outcome of Brazil's presidential election, when Flavio Bolsonaro was favored at roughly 80% the day before incumbent President Luiz Inacio Lula da Silva won the runoff. Kalshi CEO Tarek Mansour said "a 5% probability doesn't mean it won't happen," according to CNBC.
For the crypto industry, a shift in congressional control could reshape the prospects for regulatory clarity. In Ohio, Defend American Jobs, part of the Fairshake super PAC network, allocated 54% of its total expenses, spending $36.9 million supporting Senator Jon Husted and $19.7 million opposing Democrat Sherrod Brown, according to its official website. Fairshake spent $40 million to help unseat Brown in 2024. Traders still expected Brown to win, with Kalshi at 72% and Polymarket at 72.5%, in line with a final New York Times/Siena poll that had him ahead 49% to 44%. Analysts have identified Brown as a potential chairman of the Senate Agriculture Committee, which oversees the Commodity Futures Trading Commission, though the leadership position remains uncertain.
In Maine, Kalshi gave Democrat Troy Jackson a 71% chance of unseating Republican Senator Susan Collins and Polymarket 71.5%, broadly in line with New York Times polls conducted in October that had Jackson ahead by two percentage points. Collins was one of four Republicans who voted against advancing the CLARITY Act in September, stalling the bill in the Senate. Advocacy group Stand with Crypto rates Jackson as strongly supportive of crypto.