Prediction markets moved quickly toward a Democratic sweep of Congress after vote counting began in the U.S. midterm elections, with Predict.fun pricing the odds of Democrats winning both the Senate and the House at 99%.
On the morning of Nov. 4, Taiwan time, Predict.fun showed a 99% probability for a Democratic win in both chambers. The market assigned 1% each to two split-control outcomes — Republicans holding the Senate while Democrats take the House, and Democrats taking the Senate while Republicans keep the House. The chance of Republicans holding both chambers fell to 0.1%.
Predict.fun is a prediction market on BNB Chain and has backing from YZi Labs, formerly Binance Labs. Pricing on other venues was similar. Prediction Hunt, which aggregates six platforms including Kalshi, Polymarket, PredictIt, Opinion and Predict.fun, also showed the probability of a Democratic sweep at about 99%.
That marked a sharp change from earlier in the day. On the afternoon of Election Day, Polymarket had put the probability of Democrats winning the Senate at only 76%. Data compiled by DeFi Rate showed that in mid-October, Kalshi and Polymarket had priced the odds of a Democratic sweep at 61% and 63%, respectively. The Senate had been the key variable in whether Democrats could sweep Congress, and less than half a day into counting, markets were barely pricing in other outcomes.
North Carolina delivers the first Senate flip of the night
At 7 p.m. Eastern Time on Nov. 3, polls closed across Georgia, South Carolina, Vermont and Virginia. Most of Kentucky and Indiana had already stopped voting at 6 p.m. Most of Florida closed at 7 p.m., with the rest of the state ending at 8 p.m. Counting began across states after polling locations shut.
According to projections from CBS News and The Associated Press, Democratic Senator Jon Ossoff won reelection in Georgia, defeating Republican Representative Mike Collins. AP called the race at 7:55 p.m. Eastern.
In North Carolina, former Democratic governor Roy Cooper defeated Republican Michael Whatley for the seat left open after Republican Senator Thom Tillis chose not to run again. It was the first Senate seat of the night to flip from Republican to Democratic control.
In New Hampshire, Democratic Representative Chris Pappas defeated former Republican Senator John Sununu, holding the seat vacated by retiring Democratic Senator Jeanne Shaheen. Virginia Senator Mark Warner won reelection, while Republicans held Florida with Senator Ashley Moody. In the House, Democrats flipped North Carolina’s 11th Congressional District.
Democrats still need three more Senate seats
Before the vote count, Republicans held 53 seats in the Senate, while Democrats held 47 seats including two independents who caucus with them. Democrats needed a net gain of four seats to win a majority. If the chamber ended in a 50-50 split, Vice President JD Vance would hold the tie-breaking vote. After the North Carolina flip, Democrats still needed a net gain of three more seats.
In the House, Republicans entered the count with 218 seats and Democrats with 214. Democrats needed a net gain of three seats to take the chamber. CBS, citing a White House official, reported that Republicans had accepted they would lose the House unless the situation changed unexpectedly. House Democratic leader Hakeem Jeffries said Democrats were about to win the majority.
Several key Senate races remain unresolved
As of 9 p.m. Eastern, several major Senate contests were still undecided. In Ohio, Republican Senator Jon Husted was facing former Senator Sherrod Brown. In Maine, Republican Senator Susan Collins was running against Democrat Troy Jackson. Michigan and Iowa both had open-seat races, while in Texas, Democrat James Talarico was facing Republican Ken Paxton.
Maine uses ranked-choice voting, and Alaska would also move to ranked-choice tabulation if no candidate wins an outright majority in the first round. Results in those two states may take several more days. The 99% figure on prediction markets reflects traders’ positions on races that had not yet been called, while the final Senate balance still depends on completed vote counts.
How the markets shifted
Predict.fun’s Nov. 4 morning board showed a 99% chance of Democrats sweeping both chambers. Earlier on Election Day afternoon, Polymarket had shown only a 76% chance of Democrats winning the Senate.
Based on the pre-election seat count, Democrats needed a net gain of four seats to control the Senate and a net gain of three seats to control the House. After the North Carolina flip, the Senate target was reduced to three more seats.
