Republican Senate seats after the 2026 midterm elections?

What would move this market

• Polls, candidate entries and withdrawals, endorsements, debates and fundraising reports; at the end, early-vote data and official results as they are counted.

How it resolves

The rules, word for word as Polymarket publishes them:

This market will resolve according to the Republican Party’s seat count in the United States Senate as a result of the 2026 United States midterm election scheduled for November 3, 2026. The seat count includes all regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026. Runoffs for qualifying elections will determine attribution of the relevant seat, even if they take place after November 2026. Vacant seats for which no election or special election to fill the seat is scheduled to take place in November 2026 as of October 31, 2026 will be treated as held by the party affiliation of the most recent member to hold that seat. For seats contested in the specified election, seats are attributed to the party under which the member was elected. If a member-elect changes party affiliation, or vacates their seat, between election day and the formal organization of Congress, the seat is attributed to the party under which the member was elected. For seats not contested in the specified election, seats are attributed to the party that holds the seat as of the date of the election. If a current sitting member of the U.S. Senate who is not up for election changes party affiliation or vacates their seat after the date of the election, the seat is attributed to the party under which the member was affiliated at the time of the election. Senate members elected as independents who formally caucus with, or, for newly elected members, who announce their intent to caucus with, the Republican party are included in the count. If the caucus decisions of members of the Senate elected as independents cannot be determined on the date of the election, this market may remain open until the earlier of (i) an announcement from the relevant members of their intents to caucus, or (ii) January 4th, 11:59 PM ET of the following calendar year. If no such announcement is made by January 4th, 11:59 PM ET of the following calendar year, the member will not count towards the seat count of any party. The resolution sources for this market will be official information from relevant state electoral authorities, the United States Congress, and a consensus of credible reporting.

Closes:

3 Nov 2026, 17:00 UTC

How results are settled:

Polymarket markets are typically settled through UMA's optimistic oracle: a result is proposed after the event, can be disputed during a challenge window, and is final once undisputed or decided.

Source market on Polymarket

How to read these odds

A share of each outcome costs its chance in cents and pays $1 if it happens, so 55% means about 55¢ a share and roughly 1.83x back if right. On a ladder of dates or levels each rung is its own yes/no market, so the prices don't add up to 100%. Guides: reading Polymarket odds, odds to probability, glossary, how election odds work.