With ten days to go until the November 4 midterms, prediction market traders have sharpened the picture of what is likely to happen in Washington and in state capitals across the country. Senate control is trading as a near coin flip, House contracts have drifted toward a narrow Republican hold, and three governor races are inside the margin where any late shift could flip the implied favorite. Below is a snapshot of what the biggest contracts on Kalshi and Polymarket are showing as of October 24, 2026, and how the week-over-week moves are reshaping the race.
Senate Control: Trading as a Toss-Up
The headline Senate control contract is where the biggest money is flowing. Republicans entered October defending a 53-47 majority with Class 2 seats on the ballot, and the market has steadily tightened as polling in Georgia, North Carolina, and Maine has converged. Current trading on the two largest venues:
| Outcome | Implied Odds | 7-Day Change |
|---|---|---|
| Republicans hold Senate | 58% | −4 pts |
| Democrats flip Senate | 42% | +4 pts |
Four weeks ago this market was trading closer to 68/32 Republican. The move has been driven primarily by narrowing polls in North Carolina and Maine, and by a steady bid under the Georgia contract where Senator Jon Ossoff is defending a seat Democrats won by less than a point in 2020.
Key Senate Race Contracts
- Georgia (Ossoff vs. Republican challenger): Democratic hold trading around 54%, a modest drift from the mid-50s where the contract has lived for most of October.
- North Carolina (Tillis defending): Republican hold at roughly 51%, the tightest competitive seat on the board.
- Maine (Collins defending): Republican hold at 61%, firmer than Tillis despite the national environment, reflecting the incumbent’s crossover appeal.
- Michigan (open seat): Democratic win at 55%, with volume concentrated in the final two weeks.
- New Hampshire: Democratic hold at 63%, drifting slightly from a 68% peak earlier this month.
For traders, the pattern is familiar from previous midterms: individual race contracts are tightening faster than the overall control contract, which usually resolves in whichever direction the two or three closest states land.
House of Representatives: Narrow Republican Hold Priced In
The House control market has moved less dramatically than the Senate but tells a cleaner story. Republicans are favored to hold the chamber, though the implied margin has shrunk as generic ballot polling has tightened.
| Outcome | Implied Odds | 7-Day Change |
|---|---|---|
| Republicans hold House | 66% | −3 pts |
| Democrats win House | 34% | +3 pts |
Traders tracking the related “net seats” contracts are pricing in Republicans losing between four and eight seats on net, keeping the chamber but with a reduced working majority. The spread of outcomes being traded is unusually narrow for this stage of a cycle, which suggests the market views the structural map as mostly set.
Governor Races: Three True Toss-Ups
Prediction markets have identified three governor contests that are genuinely in play as the campaign closes:
- Georgia: Open seat trading at 52% Republican, 48% Democrat. The contract has swung back and forth all month on turnout modeling.
- Nevada: Republican hold at 54%, with the Democratic challenger closing after the final debate.
- Michigan: Democratic hold at 57%, firmer than Nevada despite similar polling, reflecting the state’s recent partisan trend.
Beyond those three, markets are showing clear favorites in the remaining competitive races. Pennsylvania and Wisconsin are trading above 70% for the incumbent party. Arizona has settled at roughly 65% Republican after a brief tightening earlier in October.
What the Movement Tells Us
Three themes are worth watching in the final ten days:
- Volatility is concentrated in Senate contracts. The Senate control market has moved more in the last two weeks than any other political contract on Kalshi or Polymarket. That is where any late news will have the biggest price impact.
- The House market is pricing in low surprise. If Democrats pick up more than a dozen seats, that would be a significant miss relative to current pricing and would move adjacent markets, including 2028 presidential nomination contracts.
- Governor races are decoupling from top-of-ticket. Markets are pricing split outcomes in Georgia and Nevada, where traders see the governor contest trading differently from the Senate contest in the same state. That has not always been the case in recent cycles.
How to Read These Odds
Prediction market probabilities are not forecasts in the traditional polling sense. They are the market-clearing price at which traders are willing to buy or sell a contract that pays $1 if the outcome occurs. A 58% contract does not mean the outcome will happen 58% of the time in a repeated-trials sense; it means the market has settled on 58 cents as the fair price given everything currently known. That price updates in real time as new polling, early-vote data, and endorsements change the information set.
For traders new to election contracts, the final two weeks are historically the highest-volume stretch of any cycle. Spreads tighten, liquidity deepens, and the correlation between individual race markets and the top-line control markets is at its strongest. For a primer on reading these probabilities, see our guide on how to use prediction markets to inform your view.
Where to Trade These Markets
The two largest venues for election contracts in October 2026 are Kalshi and Polymarket, each with different strengths:
- Kalshi runs CFTC-regulated election contracts for US residents, including Senate control, House control, and individual race markets. Volume on the Senate control contract has topped $40 million this cycle.
- Polymarket offers crypto-settled contracts with deeper international liquidity. Governor race markets and some of the more granular turnout and margin contracts are concentrated here.
Traders who want to compare pricing across venues before placing a position can start with our PredictWire rankings of the top prediction markets, updated weekly through Election Day.
Odds in this article reflect prediction market trading as of October 24, 2026, and are rounded to the nearest percentage point. Markets are live and prices change continuously; check the venues above for the most recent quotes before trading.