Will the Republican Party control the Senate after the 2026 Midterm elections?

Polymarket traders priced "Will the Republican Party control the Senate after the 2026 Midterm elections?" at 36% as of Oct 3, 2026, 15:47 UTC, down from 38% a week earlier.

As of Oct 3, 2026, 15:47 UTC. Source: Polymarket gamma API, market 562794. Method and limitations.

Probability history

Gridlines at 25, 50 and 75 percent. History covers the recorded price path of the YES outcome.

History in numbers

Since Jul 20, 2026, this market has traded between 35 percent (Sep 22, 2026) and 56 percent (Jul 20, 2026), across 3,490 recorded prices. The current price of 36 percent is 2.0 percentage points below where it stood 7 days ago (38 percent), and 14.0 percentage points below where it stood 30 days ago (50 percent).

Weekly closes

Market liquidity

The best bid for YES is 35 percent and the best ask is 36 percent, a spread of 1.0 percentage points. Within 1 percent of the mid price the book holds no order on the bid side (the band sits inside the spread) and no order on the ask side (the band sits inside the spread). The band is 1 percent of the mid, here 0.35 cents either side, which is narrower than the distance from the mid to the best quote, so it measures nothing on this book. Resting at the best quotes instead: $9K at the best bid and $66K at the best ask.

A tighter spread means the two sides agree more closely on the price. Depth indicates how much can trade near the current price.

Order book captured 2026-10-03 15:36 UTC.

Market details

Venues: Polymarket

How this market resolves

The market currently prices the YES outcome at 36 percent, with the NO outcome at 64 percent. This is read as the crowd's probability estimate for this event, not a forecast or advice.

This market will resolve according to the party that controls the Senate following the 2026 U.S. Senate elections scheduled for November 3, 2026. Senate control is defined as having more than half of the voting Senate members, or half of the voting Senate members and the Vice Presidency. If the outcome of this election is ambiguous given the above rules, this market will remain open until the Majority Leader of the US Senate is selected following the 2026 US general election, at which point it will resolve to the party the majority leader is affiliated with at the time of their election to that position. If the elected majority leader does not caucus with any listed party this market will resolve “Other”. Determination of which party controls the Senate after the 2026 US Senate elections will be based on a consensus of credible reporting, or if there is ambiguity, final federal and/or state election authority certification or other final official determination of the 2026 election results.

More politics markets

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Background reading

Evergreen explainers from Kresmion Learn on how prediction-market prices work.

Cite this data

Kresmion stores the venue's YES price on a fixed capture schedule. The figures here are those stored prices and the differences between them, not a Kresmion estimate.

Upstream: Polymarket gamma API, market 562794

Kresmion, "Will the Republican Party control the Senate after the 2026 Midterm elections? (prediction market probability)", data as of 2026-10-03, https://kresmion.com/odds/will-the-republican-party-control-the-senate-after-the-2026-midterm-elections. Upstream data: Polymarket gamma API, market 562794.

Link to this data (HTML):

<a href="https://kresmion.com/odds/will-the-republican-party-control-the-senate-after-the-2026-midterm-elections">Will the Republican Party control the Senate after the 2026 Midterm elections? (prediction market probability) (Kresmion)</a>