2026 Midterm Election Odds & Date: November 3, 2026
House control, Senate control and combined balance-of-power markets before the U.S. federal election on Tuesday, November 3, 2026.
Market snapshot: September 23, 2026 at approximately 12:49 UTC · Previous snapshot: August 22, 2026 · Next planned refresh: October 20, 2026
The answer first
The 2026 U.S. midterm election is Tuesday, November 3, 2026. Every voting House seat and roughly one-third of Senate seats are in the regular cycle. At the September 23 snapshot, Polymarket displayed Democratic House control at 93.5%, Democratic Senate control at 65.5% — up from 50.5% on August 22, on a board that showed 55.5% for Republican control on August 5 — and a Democratic sweep as the largest combined balance-of-power outcome at 65.5%. Those percentages are changing YES prices under specific contract rules—not vote shares, polls, endorsements or guaranteed forecasts.
Polymarket 2026 midterm snapshot
House control
Republican control: 7.5%. Event volume: about $12.18M; 24h volume: $85.5K; liquidity: about $1.36M.
September 23 snapshot—not live odds →Senate control
Republican control: 34.5%. The board was near a coin flip (50.5% D) on August 22 and favored Republicans on August 5. Event volume: about $5.03M; 24h volume: $49.3K; liquidity: about $1.02M.
September 23 snapshot—not live odds →Balance of power
R Senate/D House: 26.5%; R sweep: 7.5%. Event volume: about $13.52M; 24h volume: $159.4K; liquidity: about $1.69M.
Outcome prices may reflect spreads →Complete September 23 outcome table
| Event | Displayed YES outcome | Price | Event volume | Liquidity |
|---|---|---|---|---|
| House control | Democratic Party | 93.5% | $12.18M | $1.36M |
| House control | Republican Party | 7.5% | $12.18M | $1.36M |
| Senate control | Democratic Party | 65.5% | $5.03M | $1.02M |
| Senate control | Republican Party | 34.5% | $5.03M | $1.02M |
| Combined control | Democratic Senate + House | 65.5% | $13.52M | $1.69M |
| Combined control | Republican Senate + Democratic House | 26.5% | $13.52M | $1.69M |
| Combined control | Republican Senate + House | 7.5% | $13.52M | $1.69M |
| Combined control | Democratic Senate + Republican House | 1.05% | $13.52M | $1.69M |
| Combined control | Other | 0.15% | $13.52M | $1.69M |
Prices are rounded from the Gamma event records fetched around 12:49 UTC on September 23, 2026. Event volume and liquidity repeat for outcomes within the same event and must not be added once per row. Small deviations from 100% can reflect bid/ask spreads and market structure. Since the August 22 snapshot, the Senate-control board moved from 50.5% to 65.5% Democratic, the House board from 87.5% to 93.5% Democratic, and the Democratic-sweep outcome from 46.5% to 65.5%; on August 5 the Senate board had shown 55.5% Republican. Those are changes in market prices, not verified electoral outcomes.
Race-level boards worth watching
Chamber-control events are the headline, but Polymarket also runs single-race boards that can move on state-specific news. Three examples active and open at the September 23 snapshot, all settling on the November 3 election:
Georgia Senate winner
Jon Ossoff (D) 94.5%; Mike Collins (R) about 5.9%. Event volume: about $163K; liquidity: about $250K. The two party books are separate, so their YES prices can sum to slightly more than 100%.
September 23 snapshot—not live odds →Closest Senate race
Iowa: 13.9%; Ohio (special): 11.8%; Alaska: 9.5%; other named states trade lower. Event volume: about $50K; liquidity: about $217K. A thin board — treat prices as rough signals only.
September 23 snapshot—thin book →Alaska governor
One of the most-traded 2026 governorship boards. Jonathan Kreiss-Tomkins was displayed near 82.8% and Bernadette Wilson near 14.5% at the snapshot; individual candidate books are thin, so verify depth before quoting any single name.
September 23 snapshot—not live odds →2026 midterm election timeline
House, Senate and combined-control contracts were rechecked: Democratic Senate control rose to 65.5% from 50.5% on August 22, House control to 93.5% and the Democratic sweep to 65.5%, while combined cumulative volume grew to about $30.73M. These are price moves, not outcomes.
House, Senate and combined-control contracts were rechecked for active/open status, prices, volume and liquidity, and race-level boards were added. The Senate-control board traded at 50.5% Democratic after showing 55.5% Republican at the August 5 snapshot — a price move, not an outcome.
The existing canonical page was refreshed after its planned review. House, Senate and combined-control contracts were rechecked for active/open status, liquidity, prices and written resolution terms.
Remaining state primaries and runoffs can remove candidate uncertainty. State election authorities—not a single national calendar—are the right source for each contest's filing, primary, runoff and ballot deadlines.
Campaign activity typically intensifies. Compare polling averages, fundraising disclosures, candidate debates and market depth; do not treat an isolated poll or headline as a complete control forecast.
Early-voting information, late debates, spending, endorsements and rating changes may increase search and market demand. Always align a source's timestamp with the price being discussed.
The Tuesday after the first Monday in November. This date follows 2 U.S.C. § 7 for House elections and is also the date stated in the three Polymarket event records reviewed here. State contests share the same date; the open-seat California governor election 2026 — one of the most-traded 2026 politics markets on Polymarket — is tracked in a dedicated guide.
Close races, recounts, runoffs or delayed certifications can keep a control contract open after voting. A price near 100% is not the same as an eligible resolution.
If control remains ambiguous, the contract language can make the first selected Speaker or Senate Majority Leader relevant to settlement.
What exactly is being predicted?
House control is a chamber outcome, not a national vote-share forecast. USAGov says all 435 voting House seats are up in every midterm and presidential election year. Polymarket defines control as more than half of voting members. The event therefore depends on enough district results to establish a chamber majority under the contract—not on which party wins more votes nationwide.
Senate control uses a different map and a tie rule. Senate terms are staggered, so roughly one-third of seats enter a regular cycle. The Senate Class II page identifies the terms ending January 3, 2027. The contract defines control as more than half of voting Senate members, or half of the voting members together with the Vice Presidency.
The balance-of-power event combines the chambers. Its mutually exclusive outcomes cover a Democratic sweep, divided control in either direction, a Republican sweep and Other. It is not safe to multiply two headline prices without checking dependence, spreads and the exact combined-event rules.
How the three market groups resolve
House event
Control means more than half of voting members. If the outcome is ambiguous, the event can stay open until the first post-election Speaker is selected and use that Speaker's party affiliation. Credible reporting is used first; final federal or state certification is the fallback for ambiguity.
Senate event
Control means more than half of voting members, or half plus the Vice Presidency. If ambiguity persists, the first post-election Majority Leader can determine the affiliated party. Credible reporting and final official determinations form the evidence hierarchy.
Combined event
The written source is the Associated Press, Fox News and NBC. The event says it resolves after all three conclusively call House and Senate control; if the three do not reach consensus, official certification governs. It also defines party affiliation and leadership fallbacks.
How to read 2026 midterm odds without confusing them with polls
A displayed YES price is commonly translated into an implied probability, but it is produced by orders in a contract with fees, a spread, available depth and a fixed resolution definition. A poll instead estimates responses in a sampled population during a stated field period. The two signals may move together, but they do not measure the same object.
At the September 23 snapshot the House event carried about $1.36M liquidity and roughly $12.18M cumulative volume; the Senate event about $1.02M liquidity and $5.03M volume. The Senate board moved 15 points in a month, from a near coin flip to 65.5%/34.5%, which shows how far a contested chamber price can travel before any vote is cast. Those details make the snapshot more interpretable than an isolated last price, but neither liquidity nor volume makes the forecast certain. For the general method, use the prediction markets vs. polls comparison and the prediction-market accuracy checklist.
Research checklist before using midterm market prices
- Separate House, Senate and combined control. They have different electoral maps, outcome sets and settlement language.
- Record a UTC timestamp. A screenshot without a time cannot be aligned reliably with polling, news or an order-book change.
- Capture bid, ask, spread, liquidity and 24-hour volume. The headline YES number alone hides market quality and potential price impact.
- Read the full resolution text. Note majority definitions, the Vice Presidency, party affiliation, leadership fallbacks, named reporting sources and certification fallback.
- Use polling averages carefully. Check field dates, sample definitions and whether a poll concerns a specific race, national environment or generic ballot.
- Distinguish candidate news from control probability. A major development in one race may matter, but it does not automatically translate one-for-one into chamber control.
- Check correlated outcomes. House and Senate prices are related, while the combined event expresses joint outcomes directly. Avoid double-counting the same political assumption.
- Recheck after the catalyst. Compare the new price and depth with the pre-event snapshot instead of narrating a move from memory.
Why search demand should rise before November 3
This is a durable date-first query rather than a story tied to one news cycle. Demand can build in waves: voters first search for the election date and what is on the ballot; later they compare House and Senate odds, polls and control scenarios; after voting they look for calls, certification and market settlement. Publishing the exact date and contract mechanics before those waves gives search engines time to crawl and reassess the canonical page.
The page already has early evidence of relevant demand: recent 28-day Google Search Console checks show a small stream of impressions at strong average positions, including visible query interest around Polymarket and the Senate. Clicks remain near zero at that scale, so the title, H1 and opening lead with the exact November 3 answer while retaining the established odds intent.
Related 2026 election research
Election-odds method
Use the election betting odds primer for implied probability, catalysts, spreads and resolution risk.
Another fixed election calendar
Brazil's first round is October 4, 2026, with a possible October 25 runoff. See the Brazil election 2026 odds guide.
A non-U.S. fixed calendar
Russia's State Duma vote took place September 18–20, 2026; preliminary results gave United Russia 355 of 450 seats, and two of the three Polymarket boards have settled. See the Russia Duma election 2026 results guide.
A same-day open state race
Wisconsin's open-seat governor election also lands on November 3, 2026: Crowley (D) vs Tiffany (R). See the Wisconsin governor election 2026 odds guide.
Another same-day open state race
Michigan's term-limited open seat — Benson (D) vs James (R), with a $201K-volume Polymarket board — is also decided November 3, 2026. See the Michigan governor election 2026 odds guide.
The funding fight before the vote
The October 1 shutdown was averted: a stopgap signed September 2 funds the government through December 11, a lame-duck deadline after the election. See the government shutdown deadline guide.
Price-change watchlist
The Polymarket biggest movers tool can flag a change for investigation; the event page remains the source for current depth and rules.
Frequently asked questions
When are the 2026 U.S. midterm elections?
Election Day is Tuesday, November 3, 2026. Federal law places House elections on the Tuesday after the first Monday in November in even-numbered years.
Are the 2026 U.S. midterm elections cancelled?
No official source reviewed for this guide indicates a cancellation. USAGov says the next midterm elections are in November 2026, and 2 U.S.C. § 7 sets the federal House election date as the Tuesday after the first Monday in November.
What is elected in the 2026 midterms?
All 435 voting seats in the U.S. House and roughly one-third of the 100 Senate seats are in the regular election cycle, alongside state and local contests.
What are the Polymarket 2026 House and Senate odds after the September 23 refresh?
At approximately 12:49 UTC on September 23, 2026, the displayed YES price was 93.5% for Democratic House control and 65.5% for Democratic Senate control, with a Democratic sweep at 65.5% in the combined balance-of-power event. On August 22 the same boards showed 87.5%, 50.5% and 46.5%. These are changing market snapshots, not polls or guarantees.
Why did the Senate control market move toward Democrats?
Across this page's snapshots the Senate-control YES price moved from 55.5% Republican (August 5) to 50.5% Democratic (August 22) and 65.5% Democratic (September 23). This page does not attribute causes; it records timestamped prices. Compare order flow, news timing and resolution rules before explaining any move.
How does the Polymarket House-control market resolve?
The event defines House control as more than half of voting members. If the result is ambiguous, it can remain open until the first post-election Speaker is selected, with official certification used if reporting remains unclear.
How do the Senate and balance-of-power markets resolve?
The Senate event defines control as more than half of voting members, or half plus the Vice Presidency. The combined event uses House and Senate control together and names AP, Fox News and NBC calls, with official certification as the fallback if all three do not reach consensus.
Are prediction-market odds the same as election polls?
No. A market price reflects orders under contract-specific rules, while a poll estimates responses from a sample. Liquidity, spread, time remaining and resolution wording all affect the market signal.
When will this 2026 midterm guide be refreshed?
The next planned review is October 20, 2026, two weeks before Election Day. The page should also be refreshed after a material rule change, major nominee change, official schedule update or substantial move in House or Senate control markets.
Related analysis on the blog
- Six Weeks to the Midterms: A Polymarket Analysis of the 7.5% Republican Sweep Lane — September 22, 2026
📈 Every live Polymarket market on the topic: 2026 Midterms odds · Senate Races odds · House Races odds · Governor Races odds
Sources and methodology
- USAGov: Congressional and midterm elections — next midterms in November 2026, all 435 House seats and staggered Senate terms; page last updated February 12, 2026.
- 2 U.S.C. § 7 — the Tuesday-after-the-first-Monday rule for House elections in even-numbered years.
- U.S. Senate: Class II — official list of Senate terms ending January 3, 2027.
- Polymarket Gamma: House control — event status, prices, volume, liquidity and resolution text.
- Polymarket Gamma: Senate control — event status, prices, volume, liquidity and resolution text.
- Polymarket Gamma: 2026 balance of power — joint outcomes, named resolution sources and certification fallback.
- Polymarket Gamma: Georgia Senate winner — party YES prices, volume and liquidity for the single-race board.
- Polymarket Gamma: closest Senate race — per-state closest-race board used in the race-level section.
- Polymarket Gamma: Alaska governor — governorship board volume and candidate-book depth.
Official pages and Gamma records were rechecked September 23, 2026 around 12:49 UTC (previous check: August 22 around 14:08 UTC). Figures are rounded for readability. This page records a timestamped research snapshot and does not claim that a displayed price will persist or predict the result with certainty.