TOTAL VOLUME:

$116.8b

24H VOL:

$74,316,137

24H TRANSACTIONS:

1,362,287,844

OPEN INTEREST:

$1,155,356,965

338,521

Markets across

33,297

events

MATCHED EVENTS:

4,228

PLATFORM COVERAGE:

5

Polymarket:

42%

VS.

Kalshi:

58%

Blue tsunami in 2026?

44%chance
Amount

$

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Outcome
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24h
7d
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Result
MUI X License key version mismatch
Total markets: 1

Intro

This market tracks whether Democrats will achieve a "blue tsunami" in the 2026 midterm elections by simultaneously holding at least 235 House seats and 51 Senate seats. On Polymarket, the probability of a blue tsunami occurring stands at 44.0%, according to the resolution criteria specified in the official market rules. Resolution will be determined by the final seat counts following the 2026 midterm elections on November 5, 2026, when both chambers' compositions will be confirmed.

Polymarket

This market will resolve to “Yes” if both of the following conditions are met as a result of the 2026 midterm elections: - Democrats have a seat count of 235 or more in the House - Democrats have a seat count of 51 or more in the Senate Otherwise, this market will resolve to “No”. The Senate 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. Vacant Senate 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. The House seat count includes all House elections in the 2026 United States midterm election that elect voting members and determine representation in the upcoming 120th Congress. Where a Senate or House seat is decided by a runoff, the runoff result will determine attribution of that seat, even if it takes place after November 2026. 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 and House members elected as independents who formally caucus with, or, for newly elected members, who announce their intent to caucus with a party are included in that party’s count. If the caucus decisions of members of the Senate or House 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

Frequently asked questions

Prediction market odds on Polymarket reflect real-money bets from traders who profit or lose based on the actual outcome, creating strong incentives for accuracy. Polling averages, by contrast, measure voter sentiment at a single point in time and can lag behind shifting political conditions. Markets typically incorporate polling data but also factor in fundraising, turnout models, and historical patterns. The 43.5% probability shown here represents aggregated trader expectations, which often diverge from polls as new information emerges closer to the 2026 election.

On Polymarket, the Blue tsunami in 2026 market is priced as a binary outcome: traders either buy YES shares (betting a blue tsunami occurs) or NO shares (betting it does not). On Polymarket, prices reflect that venue's order book, liquidity, and how traders price the outcome right now. The current price reflects 43.5% probability for YES, meaning each YES share is worth approximately that percentage of the full payout. As traders adjust their positions based on political developments, campaign momentum, and polling shifts, the price moves in real time. Higher trading volume typically indicates greater confidence in the market's pricing.

The Blue tsunami in 2026 market resolves on Nov 30, 2026, following the 2026 midterm elections. Resolution depends on whether the specific criteria for a blue tsunami—typically defined as significant Democratic gains in the House, Senate, or both chambers—are met. The exact threshold and definition are established in the market's terms at creation. Traders should review the full resolution criteria on Polymarket before placing positions, as edge cases or disputed results may require clarification from the platform's resolution team.

Key catalysts include major shifts in generic ballot polling, economic data releases, approval ratings, and significant political events or scandals. Midterm-cycle fundraising reports and candidate recruitment announcements can reshape expectations for specific races. Special elections, redistricting outcomes, and changes in voter registration also influence the likelihood of large Democratic gains. Media coverage of turnout models, demographic shifts, and historical precedent for the sitting president's party performance will likely drive trading volume and price movement on Polymarket as 2026 approaches.