The Prediction Markets

How many Democratic House Incumbents will not win their Primary?

Closes
TBD
Traded
$67K
Venues
Polymarket
Prices updated
just now
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What the markets expect

10-12 94.7%

Next is 13-15 at 5.3%. Only Polymarket lists this market, so there is no second price to compare.

10-12 94.7%13-15 5.3%

Odds by venue

Fair chance strips out each venue’s built-in margin (its prices add up to more than 100%), then blends the venues by how much has traded there, so the outcomes add up to 100%. Best Yes price is the cheapest ask across venues, and the payout is what a winning $100 stake returns before fees. Open a row for each venue’s contract name, bid and ask, and how closely their rules match.

Prices come from our regular polls of each venue. Ages are as of when this page was built.

  • Polymarket
10-12
94.7%
Polymarket 93.1%(94.7% fair)polled, 34s agoBest Yes 94.2¢ on Polymarket, $100 pays $106 (1.06x)
Polymarket
Contract
10-12
Last price
93.1%
Fair, margin removed
94.7%
As of
Polled just now
Buy Yes
94.2¢
Sell Yes
92¢
$100 on Yes pays
$106 (1.06x)
Volume
$22K
Trade this on Polymarket
13-15
5.3%
Polymarket 5.2%polled, 34s agoBest Yes 8.2¢ on Polymarket, $100 pays $1,220 (12.2x)
Polymarket
Contract
13-15
Last price
5.2%
As of
Polled just now
Buy Yes
8.2¢
Sell Yes
2.2¢
$100 on Yes pays
$1,220 (12.2x)
Volume
$9K
Trade this on Polymarket

Who resolves this market

Polymarket
Polymarket resolves via:
UMA optimistic oracle

How the odds have moved

The top 2 outcomes on both venues, with the consensus between them. Hover for exact values.

  • 10-12
  • 13-15

Order books

Each venue’s resting orders for the selected outcome’s Yes contract, side by side. Top of book streams live; depth refreshes every 15 seconds.

Polymarket

Open on Polymarket ↗

Top of book

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Depth · top 8 levels

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Recent trades

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What your stake buys

Enter a stake to see where it buys the most after fees, using each venue’s live order book.

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Cover all 2 outcomes across venues

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Buys at the asks resting now (taker orders), cheapest after fees first, from order-book snapshots up to 15 seconds old. Fees: Kalshi 0.07 × price × (1 − price) per share, rounded up to the cent; Polymarket 0.04 × price × (1 − price) per share (politics rate). Fee calculator. Estimates only, not advice.

About this market

Live prediction market odds for "How many Democratic House Incumbents will not win their Primary?". 10-12 leads at 94.7%. Next is 13-15 at 5.3%. $67K has traded across 2 outcomes on Polymarket.

The 2026 midterm elections are scheduled to be held on November 3, 2026, with congressional primaries running from March through September. This market will resolve according to the number of Democratic House incumbents who do not win their nominating election to move on to the general election as a result of the 2026 midterm primary elections. An incumbent will be considered not to have won their election if they are not declared the winner of the election they sought, including if they withdraw, suspend, or otherwise leave the race at any point after officially registering as a candidate, regardless of the reason. Incumbents who do not officially register as candidates for reelection will not be considered. This market will resolve based on the results of all House nominating elections, including party primaries, top-two or jungle primaries, and primaries for special elections, that are scheduled to occur between March 1 and September 30, 2026. If a required runoff for any such election or a subsequent qualifying round in a non-partisan primary system could change the market’s outcome, the market will remain open until that contest is conclusively called by this market’s resolution sources. A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time of their nominating election. Members of the House of Representatives who are "delegates” or “resident commissioners” not chosen by the people of a state are not included for purposes of resolving this market. The resolution source for this market will be the Associated Press, Fox News, and NBC. This market will resolve once all three sources have conclusively called all relevant nominating elections. If all three sources do not achieve consensus in calling the relevant races for this market, it will resolve based on official state certification of the nominating election results.

Questions

What does the consensus price mean?

It is the price of a Yes contract that pays $1 if the outcome happens. A 14¢ price means traders put the chance near 14%. Where two venues list the same outcome, we blend their last prices, weighting the venue with more trading volume more heavily (neither counts for less than a quarter). When only one outcome can win, each venue’s prices add up to a little over 100% (its margin); the fair chance removes that margin so the outcomes add up to exactly 100%.

How is the payout worked out?

A Yes contract pays $1 if it wins, so at the best ask a $100 stake buys 100 ÷ ask contracts. At 18¢ that is about 555 contracts, paying $556 (5.56x) if Yes happens. Venue fees and price slippage on larger orders are not included.

Why do the venues show different prices?

Each venue has its own traders, fees and order book. Contracts can also settle on slightly different terms, which is why each row lists how closely the rules match.

Is a price gap an arbitrage?

Only when you can buy Yes on one venue below what someone pays for Yes on the other, after fees, and both contracts settle the same way. We show the executable bid and ask so you can check.

How fresh are these prices?

Venue prices refresh every few minutes, and the order book and live quotes stream continuously. Each venue’s card shows when we last observed it.

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