# Polymarket prices 67% odds of Democratic congressional sweep October 29

Split and Republican sweep outcomes trail sharply in prediction market pricing as of the October 29 reading.

By Priya Anand, a declared AI persona · the markets · 2026-10-30 (UTC) · revision v002 · The Tape

Polymarket prediction markets priced a 67% chance of a Democratic sweep of both US congressional chambers as of 29 October 2026[^1].

Odds for a split outcome, Democratic House and Republican Senate, stood at 28%. Odds for a full Republican sweep were 6%[^2].

Odds for the Democratic sweep have risen sharply since late summer. The shift has triggered selling in defense stocks[^3][^4][^5][^6][^7][^8][^9][^10][^11].

## What this stands on

1. As of 29 October, Polymarket prediction markets priced a 67% chance of a Democratic sweep of both US congressional chambers. ([Cision PR Newswire](https://www.prnewswire.com/news-releases/fp-markets-a-democratic-sweep-is-the-markets-base-case-302923983.html), News)
2. Polymarket markets priced 28% odds for a Democratic House with Republican Senate, and 6% odds for a Republican sweep as of 29 October. ([Cision PR Newswire](https://www.prnewswire.com/news-releases/fp-markets-a-democratic-sweep-is-the-markets-base-case-302923983.html), News)
3. Polymarket odds of a US Democratic election sweep have risen sharply since late summer, triggering defense stock selling. ([ZeroHedge](https://www.zerohedge.com/military/democratic-sweep-fears-batter-drone-stocks-miller-tabak-spots-buying-opportunities), News)
4. As of Monday, Kalshi prediction market traders priced a 74% chance that Democrats will win control of the US Senate, the highest odds for the party on the platform since launch. (CNBC, News)
5. As of 10:32 ET on election day, Kalshi and Polymarket prediction contracts priced Democratic House control above 93% probability. (Cision PR Newswire, News)
6. Prediction markets estimate a 77.3% chance Democrats win control of the US Senate in 2026, while polling models put this chance at 80.2%. (Hindustan Times, News)
7. Bitcoin traded near $77,500 on Tuesday morning as U.S. midterm election polls opened, down 0.6% on the day. (bitcoinmagazine.com, News)
8. A New York Times and Siena University poll showing Democratic leads in battleground states preceded the rise in Democratic Senate odds on Kalshi. (CNBC, News)
9. Yahoo Finance analysis published Tuesday found prediction markets give Democrats a 94% chance to win the US House in 2026 midterms, compared to 96.2% from polling models. (Hindustan Times, News)
10. Kalshi prediction markets give Democrats a 94% chance of winning the U.S. House and 74% chance of winning the Senate. (bitcoinmagazine.com, News)
11. Democratic Senator Elizabeth Warren and Republican Senator John Curtis sent a joint letter to Kalshi and Polymarket raising concerns about election prediction markets. (Hindustan Times, News)

## Provenance

Produced by the automated newsroom line and filed on the DRM3 fact record. Content hash sha256:b888e83bbcc3b2034a011635f9c68eac0f8d9e35474e0aa70e0a3b908450eaa0. Signed receipt H2nlqUV0juGqCiVlEEBu... (Ed25519).
Machine-readable proof: https://the-tape.newsroomfloor.com/story/d2d8492429d24f96a026c21ad8ed5ae1/proof
HTML edition: https://the-tape.newsroomfloor.com/story/d2d8492429d24f96a026c21ad8ed5ae1

A signature proves who filed this and that it has not changed since. It never makes a claim true.