The Prediction Markets

2026 U.S. Senate Election: Democrats flip Republicans by March 31?

Closed
Mar 31, 2026
Traded
$92K
Venues
Polymarket
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This market has closed

Trading ended on Mar 31, 2026. The prices below are the last ones before it closed and no longer update. Browse open markets

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, the oldest 223 days ago. Ages are as of when this page was built.

  • Polymarket
Yes
100%
Polymarket 100%polled, 5357 h ago
Polymarket
Contract
Yes
Last price
100%
As of
Polled 223 d ago
Buy Yes
—
Sell Yes
99.9¢
Volume
$92K
Trade this on Polymarket

Who resolves this market

Polymarket
Polymarket resolves via:
UMA optimistic oracle

How the odds have moved

The leading outcome on both venues, with the consensus between them. Hover for exact values.

  • Yes

About this market

Final prediction market prices for "2026 U.S. Senate Election: Democrats flip Republicans by March 31?". Yes last traded at 100%. $92K has traded across 1 outcome on Polymarket. The market closed on Mar 31, 2026.

This market will resolve to “Yes” if, between the Democratic Party and the Republican Party, the Democratic Party becomes the favorite in the "Which party will win the Senate in 2026?" market (https://polymarket.com/event/which-party-will-win-the-senate-in-2026?tid=1764796601244) for any four-hour period ending by March 31, 2026, 11:59 PM ET or earlier. Otherwise, this market will resolve to “No”. The Democratic Party will be considered to have become the favorite for any four-hour period if it is ahead of the Republican Party in more individual minutes than the Republican Party is ahead of the Democratic Party during a qualifying time period. A tie in the number of minutes will not qualify. The resolution source will be the underlying minute-level price data for the “Which party will win the Senate in 2026?” market, which can be viewed using the bar chart on https://derivative.polymarket.com/index/2026-us-senate-election-democrats-flip-republicans-by or through the “Resolution” tab with the time set to show the four-hour window. Both interfaces display the same underlying data. Note: This market will resolve according to the price scoring methodology of derivative.polymarket.com.

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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