Prediction markets largely anticipated the outcome of the 2026 midterm elections, with Democrats winning control of both the House and Senate. Kalshi and Polymarket priced Democrats as favorites heading into Election Day, though several races produced surprises.
The results offer an important test of political prediction markets: How accurately did traders price election outcomes before voting ended, which races surprised them, and what can we learn from the biggest market misses?
Below, we compare pre-election probabilities with actual results, examine the most notable upsets, and explore how trading volume and market liquidity may have affected prices.
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Did prediction markets correctly predict the 2026 midterms?
At the national level, both Kalshi and Polymarket priced the eventual Democratic House and Senate victories as more likely than the alternatives.
House midterm odds were more decisive, with both platforms assigning Democrats more than a 90% chance of taking control before the first polls closed.
Senate midterm odds were less certain. Kalshi and Polymarket priced Democratic control at approximately 75%, leaving roughly a one-in-four implied chance of a Republican majority.
Both markets ultimately identified the winning party in each chamber, but correctly identifying a favored outcome is only one measure of forecasting accuracy.
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Kalshi vs. Polymarket: 2026 Election accuracy scorecard
Compare market probabilities immediately before the first polls closed with the final election results.
| Market | Kalshi Pre-Close Odds | Polymarket Pre-Close Odds | Result |
|---|---|---|---|
| Democratic House control | 93% | 95% | Democrats won |
| Democratic Senate control | 75% | 75% | Democrats won |
How accurate were the markets?
Prediction markets were directionally correct on both chambers of Congress, but those two results alone aren't enough to determine which platform forecast better.
A more meaningful assessment looks at probabilities across dozens or hundreds of comparable contracts.
For example, outcomes priced at 70% should occur approximately 70% of the time across a sufficiently large sample of similarly priced events. An outcome with a 30% probability of winning is not necessarily evidence of a bad forecast.
Why midterm odds can add up to more than 100%Biggest prediction market upsets in the 2026 Midterms
Although the national markets anticipated Democratic control of Congress, individual contests told a more complicated story.
South Carolina Senate: Annie Andrews defies market expectations
Democrat Annie Andrews defeated Republican Darline Graham in one of the election's most notable prediction market upsets.
Before the results, prediction markets had priced Graham at approximately 70% to win. Andrews' victory demonstrates why a substantial market favorite is never a guaranteed winner.
The result also illustrates the importance of evaluating lower-probability outcomes across many races rather than treating one upset as proof that an entire market failed.
Texas Governor: Gina Hinojosa defeats Greg Abbott
Another notable surprise came in Texas, where Democrat Gina Hinojosa defeated incumbent Republican Governor Greg Abbott.
Prediction markets priced Abbott as the more likely winner at about 65% on the morning of Election Day. The result became another example of a competitive race where the outcome diverged from the market's earlier expectations.
Other notable results
- Iowa Senate, where Josh Turek defeated Ashley Hinson.
- Maine Senate, where Troy Jackson defeated Susan Collins.
- Michigan Senate, where Abdul El-Sayed defeated Mike Rogers.
- Texas Senate, where James Talarico defeated Ken Paxton.
- Ohio Senate, where Sherrod Brown defeated Jon Husted.
How did prediction market odds change on Election Night?
Prediction market prices shifted rapidly once election results began arriving.
Before polls closed, Kalshi and Polymarket had assigned Democrats roughly a 75% chance of Senate control. As results came in, the probability rose sharply.
By 7 p.m. ET, Democratic Senate control had risen to 89% on Kalshi and 90% on Polymarket.
Both platforms moved above 99% for control of both chambers later that evening.
Were prediction markets more accurate than traditional polls?
The 2026 elections offer an opportunity to compare two different approaches to forecasting elections.
Polls measure voter preferences among surveyed populations, while prediction markets reflect the prices traders are willing to pay for outcomes.
In several major races, polling and prediction markets broadly aligned with the eventual result. In other contests, including South Carolina, the information available before Election Day did not fully anticipate the outcome.
A meaningful comparison should evaluate both sources across the same races and dates, rather than focusing only on the most dramatic misses.
Midterm Election Battleground States Results
Senate control races and Governors’ Mansion races across America typically come down to key battleground states. With statewide races heating up everywhere, many key states had plenty of interesting races.
- Alaska Midterm Odds
- Florida Midterm Odds
- Georgia Midterm Odds
- Iowa Midterm Odds
- Maine Midterm Odds
- Michigan Midterm Odds
- Texas Midterm Odds
How to read midterm prediction market odds
Prediction markets don’t price outcomes like a traditional sportsbook, but their odds are intuitive. If a party has a $0.62 price, the market is saying there’s a 62% chance it will happen.
Prediction markets aren’t polls; they’re the consensus of what traders in that market think will happen.
Markets with more trades and more dollars traded tend to be more stable, but newer or less-traded markets may move significantly as people start trading.
Additionally, polls and predictions can move traders’ opinions. Polls capture where a race stands at the time of the poll, whereas prediction markets focus on what will happen.
Models attempt to use quantifiable information, including polls and other metrics, to predict the current state of play.
2026 midterm results FAQ
Kalshi's pre-election markets favored Democratic control of both the House and Senate, and Democrats won both chambers. Individual market performance varied by race.
Polymarket also priced Democrats as the more likely winners of both chambers before polls closed. Some individual race outcomes differed from the market's favored result.
South Carolina's Senate election and Texas's governor election were among the most notable surprises, with outcomes that diverged from the pre-election market favorites.
Accuracy depends on the markets examined, the timing of recorded prices and the measurement method. A high favorite-win percentage does not necessarily establish well-calibrated probabilities.
Contracts settle according to the operator's specific market rules. Some may resolve quickly, while others can remain pending until required sources confirm the outcome.
