Industry Data
2026 Midterm Election Volume
Contracts traded on 2026 US election race markets, from each venue's own trade records. The first chart adds every race together. The charts below split it into House and Senate, governor and other statewide, and mayoral races. Each market is reviewed before it is counted, and it is counted once, in one chart only. Primaries are not included.
Totals for the selected dates
Weekly 2026 Election Race Notional Volume
Learn more about election race volume
Contracts traded on 2026 US election race markets, counting one side of each trade: the congressional, governor and mayoral races shown separately below, added together. Each market is counted once.
Weekly 2026 Midterm Race Notional Volume
Learn more about midterm race volume
Contracts traded on the 2026 House and Senate elections: control of each chamber, the balance of power, seat counts and every House and Senate race on 2026-11-03. Primaries are not included. Each market is counted once.
Weekly 2026 Governor Race Notional Volume
Learn more about governor race volume
Contracts traded on 2026 governor races and other statewide offices, such as attorney general and secretary of state. Primaries are not included. Each market is counted once.
Weekly 2026 Mayoral Race Notional Volume
Learn more about mayoral race volume
Contracts traded on 2026 US mayoral races, which are local and counted apart from the races above. Each market is counted once.
Weekly 2026 Midterm Contract Notional Volume
Learn more about midterm contract volume
Contracts traded on every 2026 midterm market, counting one side of each trade: the House, Senate, governor and other statewide races decided on 2026-11-03, and other contracts on that election such as margins, turnout, Trump endorsements and state ballot measures. Primaries and mayoral races are left out because they were not decided on 2026-11-03. Markets count whether they have resolved or are still open, and each market is counted once. Combos are not included.
Weekly Other 2026 Midterm Contract Notional Volume
Learn more about other midterm contract volume
Contracts on the 2026-11-03 election that are not about who wins a single race: margins of victory, closest race, turnout, the popular vote, when races are called, Trump endorsements, state legislature control and state ballot measures. Each market is counted once.
Weekly 2026 Midterm Primary Notional Volume
Learn more about midterm primary volume
Contracts traded on the 2026 primaries, runoffs and special elections for the House, Senate, governor and other statewide offices, including who wins each party's nomination. They are counted apart from the midterm contract charts above, which only cover what was decided on 2026-11-03. Each market is counted once.
FAQs
Common questions about prediction market data and how it’s calculated.
Are prediction markets becoming more popular?
Yes. Trading volume has grown sharply through 2026, with monthly totals across major platforms reaching into the tens of billions of dollars. Kalshi and Polymarket regularly appear in national news coverage, and have struck data and distribution partnerships with major names like Robinhood, CNBC, CNN and Google Finance.
What are the top 10 prediction markets?
Kalshi and Polymarket lead by volume, followed by platforms like Novig, ProphetX, and Underdog. The answer really depends on the features most important to you, like range of markets, fees and trading experience. See our list of prediction market apps for a detailed breakdown of each platform’s strengths.
Which prediction market app is the most accurate?
There’s no single answer. Accuracy or calibration will vary by platform, market and time period. Generally, higher liquidity and trading activity mean more stable pricing on event contracts. You can also look at platforms’ price and trade history over time to inform your opinion. Try our Kalshi and Polymarket historical data guide as an example.
Who are the biggest players in prediction markets?
Kalshi and Polymarket are the two largest platforms by volume and user activity, together accounting for the large majority of industry-wide trading. The gap between the two shifts week to week depending on the sports calendar, news cycle and major events.
Contact us
Want to request data or get download access?
Whether you need numbers for your own work, want a chart added to this page or need the data behind it, send me a message on Telegram or X, or email the team at [email protected].
dash
Industry Data Lead
dash has 6 years of experience as a data scientist and has created the most cited Prediction Market dashboards.