Future Index
Forecast marketsPolymarketOpenUp to date

2026 Balance of Power: D Senate, D House

Probability

60.5%

somewhat likely

Computed from this source alone. Observed .

Movement

Change in probability, in percentage points (pp).

  • 1 hour+2.0 ppup over 1 hourfrom 58.5% at
  • 24 hours+4.0 ppup over 24 hoursfrom 56.5% at
  • 7 days+10.0 ppup over 7 daysfrom 50.5% at
  • 30 daysNo baseline this far back

History — last 7 days

Probability over the last 7 days: 167 readings from 09-10 00:22 to 09-16 22:21 UTC. Starts at 50.5%, ends at 60.5%, ranging between 49.5% and 60.5%. 166 gaps where the source reported nothing, joined by a straight line rather than measured.0%25%50%75%100%09-0909-1109-1309-1509-16
Probability, 0–100 %. Times UTC. Where the source reported nothing, the two readings either side are joined by a straight line rather than measured.

Volatility

How much the probability has been moving, in probability units per √hour. Scaled by elapsed time, so a source polled often and one polled rarely produce comparable figures.

  • 1 hourNot enough readings1 increment
  • 24 hours0.005024 increments
  • 7 days0.0039168 increments
  • 30 days0.0030334 increments

Confidence and coverage

Confidence describes how well supported the number is and never how large it is.

High confidence0.79
1 sourceForecast markets1

Manipulation risk: low. Method version 1.0.0.

How this is calculated
Source
PolymarketForecast marketsPolymarket
Freshness
Up to dateUp to dateRead at 2026-09-16T22:21:08.210Z, calculated at 2026-09-16T23:16:11.893Z.
Participation behind it
$247,022 of depth
How easily it could be moved
Enough participation that moving this number would take a substantial position.
Method version
1.0.0Stored on this value; it identifies the code that produced it.

Probability 0.61

The source's own most recent published probability for this question, unchanged. Full method for probability

Change over time

How far the probability has moved over each window, in probability points. Full method for change over time

  • 1h+2.0 points up, measured from 0.59 at 2026-09-16T21:21:08.204Z
  • 24h+4.0 points up, measured from 0.57 at 2026-09-15T22:21:09.231Z
  • 7d+10.0 points up, measured from 0.51 at 2026-09-09T22:22:06.079Z
  • 30dNo reading far enough back to measure from — not the same as no movement.

Variability

How much the probability has been moving about within each window. Full method for variability

  • 1hOnly 1 change in this window — too few to estimate from.
  • 24h0.005 probability units per √hour, from 24 changes
  • 7d0.004 probability units per √hour, from 168 changes
  • 30d0.003 probability units per √hour, from 334 changes

Confidence 0.79 — High

How well supported this source's number is — never how large, how recent, or how interesting the number is. Full method for confidence

  • Participation behind the contract1.00, carrying 40% of the score
  • Age of the newest reading0.69, carrying 30% of the score
  • Distance between the quoted sides0.90, carrying 20% of the score
  • Time until the question settles0.34, carrying 10% of the score

Coverage

Which sources stand behind a number, and which do not. Full method for coverage

  • This figure comes from Polymarket alone. Future Index does not combine forecasts from different sources into one number — why.
  • The source states no language or geographic scope for this question, so none is claimed here.

Read the full methodology

What was reported

Occurrences on the topics this contract is linked to. Each entry is one occurrence, however many outlets carried it.

  1. US Congress passes Russia sanctions bill

    1 independent origin · low confidence

    Reports

    Deutsche Welle

  2. House holds billionaire Leon Black in contempt of Congress

    1 independent origin · low confidence

    Reports

    NPR

  3. Congress is under pressure to act on AI — here's what that could look like

    1 independent origin · low confidence

    Reports

    NPR

17 further occurrences on this page — show them

  1. A tumultuous congressional primary season closes with record departures and defeats

    1 independent origin · low confidence

    Reports

    NPR

  2. Why are election officials in the US preparing for chaos before midterms?

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  3. Republican forces Congress to hold impeachment vote for Pete Hegseth

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  4. US Senate crypto bill collapses in blow to industry

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  5. First Secretary of State Louise Haigh's speech to the Trade Union Congress 2026.

    1 independent origin · medium confidence

    Reports

    Contains public sector information licensed under the Open Government Licence v3.0.

  6. US Supreme Court rejects Trump mail ballot restrictions ahead of midterms

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  7. The Supreme Court rejects Trump's mail voting restrictions for this year's midterms

    1 independent origin · low confidence

    Reports

    NPR

  8. Mitch McConnell returns to Senate after fall that led to an extended medical absence

    1 independent origin · low confidence

    Reports

    NPR

  9. Remembering 9/11.

    1 independent origin · low confidence

    Reports

    NPR

  10. Trump jokes Republicans can ‘cheat like hell’ in the midterms

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  11. Jimmy Kimmel moves Senate interview to YouTube in latest collision with FCC

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  12. The Trump-to-Mamdani voter is real.

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  13. Trump promises $5,000 payouts if GOP wins midterms: Can the US afford it?

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  14. Trump says every adult American would get $5,000 if Republicans win midterms

    1 independent origin · low confidence

    Reports

    BBC News

  15. Trump: Every American gets $5,000 if Republicans win House & Senate

    1 independent origin · low confidence

    Reports

    Al Jazeera English

  16. Four takeaways from Trump's speech at first Republican midterms convention

    1 independent origin · low confidence

    Reports

    BBC News

  17. Trump promises Americans $5,000 if Republicans win midterms

    1 independent origin · low confidence

    Reports

    Deutsche Welle

Resolution

Settlement rules: Not available.

Source

  • SourcePolymarket
  • KindForecast markets
  • Contract id0x16c63b7cc37f012b9f59ee164ec03877914c701d06d48291ae8d6fc08a088b0d

Polymarket

This source's terms require a link back to the contract. Future Index does not yet store one, so the identifier above is shown instead.

Topics

  • us-congress

Last observed . Page built .