The Prediction Markets

Which party will win the U.S. House?

Starts in 12 daysKickoff
Traded
$86.0M
Venues
Polymarket, Kalshi
Prices updated
just now
Share

What the markets expect

Democratic 91.7%

Next is Republican at 8.3%. The venues differ most on Democratic (Polymarket 92.5%, Kalshi 91.4%), a 1.1-point gap.

Democratic 91.7%Republican 8.3%

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.

2 of 4 prices are live from the exchange feeds; the rest come from our regular price polls, the oldest 1 min ago. Ages are as of when this page was built.

  • Polymarket
  • Kalshi
DemocraticArb
91.7%
Polymarket 92.5%live, 45s agoKalshi 91.4%live, 35s agoBest Yes 91.4¢ on Kalshi, $100 pays $109 (1.09x)
Polymarket
Contract
Democratic Party
Price
92.5%
As of
Live feed, just now
Buy Yes
93¢
Sell Yes
92¢
$100 on Yes pays
$108 (1.08x)
Volume
$11.8M
Trade this on Polymarket
Kalshi
Contract
Democratic Party
Price
91.4%
As of
Live feed, just now
Buy Yes
91.4¢
Sell Yes
91.3¢
$100 on Yes pays
$109 (1.09x)
Volume
$21.3M
Trade this on Kalshi
Partial parity

Payoffs match in ordinary outcomes; see the rule differences below the table.

Buying on Kalshi at 91.4¢ and selling on Polymarket at 92¢ nets 60 bps before fees.

RepublicanArb
8.3%
Polymarket 7.5%polled, 1 min agoKalshi 8.6%polled, 1 min agoBest Yes 8¢ on Polymarket, $100 pays $1,250 (12.5x)
Polymarket
Contract
Republican Party
Last price
7.5%
As of
Polled 1 min ago
Buy Yes
8¢
Sell Yes
7¢
$100 on Yes pays
$1,250 (12.5x)
Volume
$8.4M
Trade this on Polymarket
Kalshi
Contract
Republican Party
Last price
8.6%
As of
Polled 1 min ago
Buy Yes
8.6¢
Sell Yes
8.5¢
$100 on Yes pays
$1,163 (11.6x)
Volume
$44.4M
Trade this on Kalshi
Partial parity

Payoffs match in ordinary outcomes; see the rule differences below the table.

Buying on Polymarket at 8¢ and selling on Kalshi at 8.5¢ nets 50 bps before fees.

Possible arbitrage before fees: buy Democratic on Kalshi at 91.4¢, sell on Polymarket at 92¢ (60 bps). Check the rules below before trading. See all live spreads

Mostly the same bet: 4 differences

Where they differ

  • Kalshi: media-consensus call, otherwise the party of the Speaker / President pro tempore on Feb 1 of the new Congress. Polymarket: majority of voting seats as elected, independents by caucus.
  • Tied Senate: Polymarket awards the Vice President's party; Kalshi follows the President pro tempore.
  • Members switching party after election day change the Kalshi outcome but not Polymarket's.
  • Trading closes at different times: Nov 4, 2026, 4:59 AM UTC on Polymarket and Feb 1, 2027, 3:00 PM UTC on Kalshi.
Polymarket
Polymarket resolves via:
UMA optimistic oracle
Kalshi
Kalshi resolves via:
Kalshi (CFTC-regulated exchange), source: Library of Congress
Show full rule comparison
  • Kalshi: media-consensus call, otherwise the party of the Speaker / President pro tempore on Feb 1 of the new Congress. Polymarket: majority of voting seats as elected, independents by caucus.
  • Tied Senate: Polymarket awards the Vice President's party; Kalshi follows the President pro tempore.
  • Members switching party after election day change the Kalshi outcome but not Polymarket's.
  • Trading closes Nov 4, 2026, 4:59 AM UTC on Polymarket and Feb 1, 2027, 3:00 PM UTC on Kalshi.

Summarized from each venue’s published rules; the venue’s own rules page is the final word.

How the odds have moved

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

  • Democratic
  • Republican

Live prices for Democratic

What it costs to buy Yes, what you would get selling it, and the last trade on each exchange, updating as orders change. Hover a status for timing details.

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.

Combined depth · both venues

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Polymarket

Open on Polymarket ↗

Top of book

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Best bid
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Best ask
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Depth · top 8 levels

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Recent trades

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Kalshi

Open on Kalshi ↗

Top of book

Connecting
Best bid
—
Spread
—
Best ask
—

Waiting for the first live quote…

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.

$
Buy

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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 0.05 × price × (1 − price) per share (other / general rate). Fee calculator. Estimates only, not advice.

About this market

Live prediction market odds for "Which party will win the U.S. House?". Democratic leads at 91.7%. Next is Republican at 8.3%. $86.0M has traded across 2 outcomes on Kalshi and Polymarket. The market is expected to resolve by Feb 1, 2027.

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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