Traders make Democrats heavy favourites to win the House

The Democratic contract climbed from 92% to 95% over the week, and the Republican side sits at 6%.

In one line: Democrats win a majority of House voting seats when the count settles on 4 Nov, as the 95% price expects.

Polymarket's contract on Democratic control of the House rose from 92% on 27 Oct to 95% on 3 Nov, up 3 points over the 7 days. It touched a 7-day high of 96% on 2 Nov and has slipped 1 point since. The market resolves tomorrow.

The Republican contract in the same event trades at 6%, so both sides of the book tell one story. Kalshi prices the House through contracts that pair it with the Senate for February 2027. Its contract for a Democratic House and a Democratic Senate stands at 74%. A Democratic House with a Republican Senate is at 20%, and a Republican House with a Democratic Senate is at 1%.

The path shows steady buying, not a jump. Traders added 3 points across a week with no single break, and a slip of 1 point since Monday's high is too small to mark a turn. The rule pays on a majority of the chamber's voting seats. Only if no party wins one does it fall back on the party of the first Speaker elected in the new Congress. A 95% price says traders expect a clear Democratic majority.

The other side's best case is a narrow count, where a sequence of close contests breaking Republican would make 5% too little room. The call is that Democrats win a majority of the House's voting seats, as the 95% price expects. It is wrong if the 4 Nov count shows a Republican majority of voting seats. An earlier warning would be the contract falling below 80% as the first races are called. If Democrats take the House, control of Congress turns on the Senate, where Polymarket's Democratic contract stands at 77%.