What Polymarket says about the 2026 US midterms

How to read this page

Each row is an open Polymarket market related to this event. The big number is the probability the market assigns today to the leading outcome: it is the contract price, not a poll. The bar shows the Yes/No split and the line, the price over the last 7 days. Data comes from Polymarket's public API and refreshes every few minutes.

Senate, House and combined markets

Midterms renew the entire House of Representatives and part of the Senate. Polymarket typically lists one market per chamber (which party controls it), a balance-of-power market that combines both (for example, a Republican Senate with a Democratic House) and markets on individual Senate or governor races.

The combined market is the easiest to misread. Its options are mutually exclusive, and its price is not the two chamber markets multiplied together, because results in both chambers tend to move in the same direction. If you want the market's view on one chamber alone, look at that chamber's own market.

What moves the price and when it resolves

Prices respond to district polling, campaign fundraising, candidates dropping out and, on election night, the pace of each state's count. Some states take days to count mail ballots, so control of a chamber can stay open after most races have been called. During those days the price shifts with every batch of votes released.

To settle, someone proposes the result to UMA's optimistic oracle with a bond, and a two-hour dispute window follows. Each market's rules define what counts as control, such as how independent senators are treated or the Vice President's tie-breaking vote. Read them before treating a price near 1 as final.

Polymarket, polymarket.us and Kalshi

The United States is close-only on global Polymarket, on both the website and the API. US residents trade on polymarket.us, a separate entity, or on Kalshi, a CFTC-regulated event-contract exchange that runs in dollars. Prices on the three platforms need not match: they are different order books with different traders. On global Polymarket, politics carries a 0.04 rate for whoever takes liquidity.

Frequently asked questions

Does Polymarket predict who wins in the United States?

It does not predict: it shows what people pay for each outcome. A 70% means the market pays 0.70 for a contract worth 1 if it happens. It is a crowd opinion backed by money, not an official forecast.

Why does the percentage move so much?

Because it is a price. A new poll, a statement or a headline moves the orders and the price adjusts within minutes. Thin markets swing more.

Can I take part from this country?

It depends on the United States's legal status. Check it in the by-country section before signing up. This site shows no sign-up links where Polymarket is blocked.

Page reviewed on October 25, 2026.