Kalshi and Polymarket give Democrats 75% odds in US midterms as crypto's Ohio race defies its biggest spender
Prediction markets put a Democratic sweep at 75% hours before voting
Hours before Americans vote in the US midterm elections, the two biggest prediction markets — sites where people trade contracts that pay out based on real-world outcomes — both favor Democrats taking control of Congress. Kalshi prices a Democratic sweep of the House and Senate at 75%, and Polymarket at 75.5%, as of 4:30 pm UTC on election day.
The election is also a record event for these markets. An analysis by The Washington Post found nearly $1.9 billion in election-related contracts had traded on Kalshi and Polymarket as of Monday — the most ever for a midterm cycle.
Key numbers
- Democratic sweep: 75% on Kalshi, 75.5% on Polymarket (4:30 pm UTC).
- Democrats win the House: 93% on Kalshi, 94.5% on Polymarket.
- Democrats win the Senate: 75% on Kalshi, 75.5% on Polymarket.
- Nearly $1.9 billion in election contracts traded as of Monday, per a Washington Post analysis.
Markets are watching closely because the last big test went badly for them. Nine days ago, prediction markets favored Flávio Bolsonaro at roughly 80% the day before Luiz Inácio Lula da Silva won Brazil's presidential runoff. Kalshi CEO Tarek Mansour reportedly cautioned that "a 5% probability doesn't mean it won't happen," according to CNBC.
Crypto's biggest Senate spend may not pay off in Ohio
The most expensive crypto-linked race is the Senate seat in Ohio. Defend American Jobs, part of the Fairshake super PAC network funded largely by crypto companies, put 54% of its total expenses into the race: $36.9 million supporting Republican Senator Jon Husted and $19.7 million opposing Democrat Sherrod Brown, a sharp crypto critic. Fairshake spent $40 million helping unseat Brown in 2024.
Traders expect the spending to fall short. Kalshi gives Brown a 72% chance of winning and Polymarket 72.5%, in line with a final New York Times/Siena poll that had him ahead 49% to 44%.
A Brown win could complicate the industry's legislative agenda, especially if Democrats take the Senate. Analysts have identified him as a possible chairman of the Senate Agriculture Committee, which oversees the Commodity Futures Trading Commission — though that leadership role remains uncertain.
Maine and the stalled CLARITY Act
Maine could cut the other way. Republican Senator Susan Collins was one of four Republicans who voted against advancing the CLARITY Act, the crypto market-structure bill, in September, stalling it in the Senate. Kalshi gives Democrat Troy Jackson a 71% chance of unseating her and Polymarket 71.5%, matching October New York Times polls that had Jackson up two points. Advocacy group Stand with Crypto rates Jackson as strongly supportive of the industry, so a win would add an ally.
Where traders break from close polls
In three states where polling is tight, traders have made clearer calls:
- Alaska: Kalshi gives Democrat Mary Peltola a 71% chance over Republican Senator Dan Sullivan, despite a final poll margin of just two points (48% to 46%). Both candidates back crypto, per Stand With Crypto.
- South Carolina: with the candidates tied at 48% in polling, Kalshi gives Republican Senator Graham, a crypto supporter, a 71% chance over Democrat Annie Andrews.
- Iowa: a toss-up on both platforms, with Democrat Josh Turek overtaking Republican Representative Ashley Hinson at 52% on Polymarket after months of Hinson being favored.
Elsewhere, markets track the polls: Democrat Abdul El-Sayed at 79% in Michigan, and Democrat James Talarico at 71% in Texas, where the final Times/Siena poll had him ahead 50% to 43%. A loss for Republican Ken Paxton would be a setback for the Digital Freedom Fund, a super PAC backed by Gemini's co-founders Cameron and Tyler Winklevoss that spent more than $81,000 supporting his campaign — though Talarico has also voiced support for the crypto industry.
Thin liquidity behind the prices
Researchers at trading firm Talos caution that the headline odds rest on thin trading. Kelly Ye, Talos' head of research, said that as of 11:30 am ET, just $300,000 of selling would have pushed Kalshi's Democrats-win-Senate contract down ten points. The median trade was around $10, with a few large trades making up most of the liquidity.
"As midterm results come in tonight, prediction markets will reprice quickly, but those prices are only as good as the liquidity behind them," she said in a statement sent to Cointelegraph. "Whatever happens tonight, one result won't tell you whether these markets are accurate. Across many settled contracts, outcomes have broadly tracked prices."
What traders price after a sweep
Polymarket's conditional markets are already looking past the vote. They imply a 35% chance of a US recession by the end of 2027 if Democrats sweep both chambers, versus 19% if they do not, as of 4:50 pm UTC.
What is confirmed and what is still unclear
Confirmed: the market prices and trading volumes reported above, the Fairshake network's Ohio spending figures, Collins' September vote against advancing the CLARITY Act, and Talos' liquidity analysis, all as reported by the source.
Still unclear: the election results themselves, whether Brown would chair the Senate Agriculture Committee, and how accurately these markets will call tight races — Brazil's runoff nine days earlier is a recent miss. The recession probabilities are trader expectations priced into contracts, not forecasts.
Sources
Newisty Editorial Team covers technology, cryptocurrency, digital products, online platforms, developer tools and the wider digital economy. Our content is researched from official sources, company announcements, public documentation, market data and other primary or reputable sources. Articles are reviewed and edited before publication for clarity, accuracy and useful context.