Sep 15, 2026
Probability rose from 76.0% to 81.5% — a 5.5-point move over the past day.
Blue Wave in 2026: Prediction Market Odds
Markets assign a 84.5% probability—strongly favored—to a Democratic blue wave in 2026, defined as control of at least 218 House seats and 49 Senate seats after the midterms.
84.5%+1.0 pts 24h
Updated · Volume $69.8K
The blue wave scenario is favored; the No side covers all outcomes where Democrats fail to hit both chamber targets.
Context
Sep 11, 2026
Probability fell from 80.0% to 78.0% — a 2.0-point move over the past day.
Sep 10, 2026
Probability fell from 80.5% to 79.0% — a 1.5-point move over the past day.
Sep 9, 2026
Probability rose from 74.5% to 81.0% — a 6.5-point move over the past day.
Sep 6, 2026
Probability fell from 88.5% to 75.0% — a 13.5-point move over the past day.
Show earlier updates
Sep 5, 2026
Probability rose from 77.5% to 90.5% — a 13.0-point move over the past day.
Aug 28, 2026
Probability fell from 81.5% to 76.5% — a 5.0-point move over the past day.
Aug 27, 2026
Probability rose from 78.5% to 81.5% — a 3.0-point move over the past day.
Aug 26, 2026
Probability rose from 73.5% to 84.0% — a 10.5-point move over the past day.
Aug 17, 2026
Probability fell from 82.5% to 76.5% — a 6.0-point move over the past day.
The chance of a blue wave now sits at 84.5%. It has drifted between 71.0% and 90.5% over the measured period and moved +1.0 pts in the past day. The line has traced an uneven path, reflecting intermittent reassessment of the political landscape. Resolution hinges on two precise thresholds: Democrats must win at least 218 House seats and at least 49 Senate seats in the 2026 midterm elections. If both bars are cleared, the market resolves Yes; failure on either count means No. The market stays open until it is confirmed that one condition cannot be met, or until both are satisfied. What would move the probability? The formal triggers are the election results themselves—no earlier milestone is built into the rules. The resolution date is Jan 5, 2027, but the market can settle earlier once outcomes are clear. Seat projections, polling, and party dynamics will feed into the price, but the rulebook points solely to the final seat tallies as the settlement source.
FAQ
What counts as a blue wave in this market?
The market defines it as Democrats holding 218 or more House seats and 49 or more Senate seats after the 2026 midterm elections.
How does the market resolve?
It resolves to Yes if both thresholds are met; otherwise it resolves to No. The full rules are published at the provided link.
What happens if one chamber flips but not the other?
That would not meet the dual requirement, so the market would resolve to No.
When does the market close?
It remains open until it is confirmed that at least one condition cannot be met, or until both conditions have been met.
Where can I find the official resolution source?
The detailed rules and source of truth are available at the link in the market description.
Data: Polymarket · Methodology · Not financial advice