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Holborn and St Pancras By-Election: Vote Share Margin of Victory
kalshi
polymarket

What will the vote share margin be?

Volume:
$33,953

Labour 10-15%

 - Polymarket

Labour 10-15% - Polymarket

1W

News

Positive

Negative

Neutral

Hover marker for details

Vol.

·

Resolved Oct 9, 2026

Closed: Oct 9, 4:34 AM EST

polymarket

Polymarket

View
Outcome
Trade
Chance %
Price
Spread
Liquidity
Volume
24h
7d
Open Interest
Ends in
Result
polymarket

Labour 10-15%

View
100%
71%
Yes 100¢No 0¢
—
N/A
$5,244
N/A
N/A
N/A
Settled
Yes
polymarket

Labour 15%+

View
0%
26%
Yes 0¢No 100¢
—
N/A
$11,979
N/A
N/A
N/A
Settled
No
kalshi

Green Party, ≥6%

View
0%
4%
Yes 0¢No 100¢
—
N/A
$4,919
N/A
N/A
$2,192
1mo 4w 1d
No
kalshi

Green Party, ≥3%

View
0%
Yes 0¢No 100¢
—
N/A
$3,956
N/A
N/A
$2,793
1mo 4w 1d
No
polymarket

Labour 5-10%

View
0%
Yes 0¢No 100¢
—
N/A
$2,051
N/A
N/A
N/A
Settled
No
polymarket

Labour 0-5%

View
0%
13%
Yes 0¢No 100¢
—
N/A
$1,290
N/A
N/A
N/A
Settled
No
polymarket

Green 10-15%

View
0%
Yes 0¢No 100¢
—
N/A
$1,145
N/A
N/A
N/A
Settled
No
polymarket

Green 5-10%

View
0%
Yes 0¢No 100¢
—
N/A
$1,000
N/A
N/A
N/A
Settled
No
polymarket

Green 0-5%

View
0%
5%
Yes 0¢No 100¢
—
N/A
$957
N/A
N/A
N/A
Settled
No
kalshi

Green Party, ≥9%

View
0%
Yes 0¢No 100¢
—
N/A
$895
N/A
N/A
$495
1mo 4w 1d
No
polymarket

Green 15%+

View
0%
Yes 0¢No 100¢
—
N/A
$418
N/A
N/A
N/A
Settled
No
kalshi

Green Party, ≥15%

View
0%
Yes 0¢No 100¢
—
N/A
$100
N/A
N/A
$100
1mo 4w 1d
No
kalshi

Green Party, ≥12%

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
1mo 4w 1d
No
kalshi

Green Party, ≥18%

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
1mo 4w 1d
No
polymarket

Another candidate wins

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
Total markets: 15

Description

This group forecasts the margin of victory in the 2026 Holborn and St Pancras by-election, triggered by Keir Starmer's resignation. Markets focus on whether the Green or Labour candidate will win, and by what margin, with some markets also considering the possibility of a win by another candidate.

PredictionHero - Resolution Divergence Alerts (RDA)

Divergence Detected

Issue: The platforms diverge in their focus; Polymarket considers Labour and other candidates, while Kalshi focuses solely on the Green Party's margin of victory.Hero tip: Consider the differing candidate focuses when trading. Polymarket offers broader coverage, while Kalshi is specific to the Green Party's performance.

Critical divergence points:

  • Polymarket: Polymarket offers markets on Labour and Green candidates winning by specific margins (0-5%, 5-10%, 10-15%) and a market for another candidate winning. Resolution relies on the official results from Camden Council and has a deadline of June 30, 2027.
  • Kalshi: Kalshi presents a series of binary markets resolving to 'Yes' if the Green Party wins by a margin of 3%, 6%, 9%, 12%, 15%, or 18% or more. There is no consideration for other candidates or Labour's performance.
Our PredictionHero Resolution Divergence Alerts (RDA) are there to help users identify potential differences across platforms. They do not replace or supersede the official rules and description of any prediction market. Users are solely responsible for reviewing and understanding the applicable rules and resolution criteria before placing any trade or bet. If you notice a potential inconsistency, discrepancy, or error in an alert, please report it to our team so we can review and improve the accuracy of our data.

Polymarket

A by-election for the United Kingdom parliamentary constituency of Holborn and St Pancras is scheduled to be held on October 8, 2026, following the resignation of incumbent Sir Keir Starmer. This market will resolve according to the margin of victory between the top two candidates in this by-election. The “margin of victory” is defined as the absolute difference between the percentages of valid votes received by the candidate who wins the most valid votes and the candidate who wins the second-most valid votes. Percentages will be determined by dividing the total number of valid votes each of the top two candidates receives by the total number of valid votes cast in the by-election. Valid vote percentages will be counted only where the official results attribute them to the candidate in question. If the reported value falls exactly between two brackets, then this market will resolve to the higher margin bracket. If a candidate standing for a party other than the Labour Party or the Green Party wins the most valid votes, this market will resolve to "Another candidate wins". If two or more candidates tie for the most valid votes, this market will resolve to the lowest margin bracket for the candidate whose party name comes first in alphabetical order. If the results of this by-election are not definitively known by June 30, 2027, 11:59 PM ET, this market will resolve to "Another candidate wins". This market will resolve based on the results of this by-election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as published by Camden Council (https://www.camden.gov.uk/).

Kalshi

The event resolves based on whether the Green Party achieves a margin of victory of at least 3%, 6%, 9%, 12%, 15%, or 18% in the 2026 Holborn and St Pancras by-election. The margin is calculated as the Green Party’s vote share minus the vote share of the candidate immediately behind them if they win, or the vote share of the first-place candidate if they lose. A positive margin indicates a win, a negative margin a loss, and zero a tie for first place. Thresholds are inclusive of their lower bounds with no rounding applied, and the maximum possible margin is 100 percentage points. In the event of an unresolved tie for first place by expiration, proportional payouts apply for ranges containing zero, while all other ranges resolve as No. Certified results, fully-conducted elections provisions, and accelerated resolution rules also apply as specified in the full rules.

Frequently asked questions

Prediction market odds often offer a distinct perspective compared to traditional polling averages. Polling reflects stated preferences, while this market reflects what people are *willing to bet* on, potentially incorporating more nuanced information and strategic considerations. While polls can be useful, they are susceptible to biases and inaccuracies. The aggregated forecasts here provide a real-money assessment of the likely outcome in the Holborn and St Pancras by-election, potentially offering a more accurate signal, especially as the election draws nearer. This market can be a valuable complement to traditional political analysis.

Prices on Polymarket and Kalshi may diverge due to several factors. Differences in trader demographics, market design, and trading fees can all contribute to price discrepancies. Polymarket and Kalshi can show different implied probabilities for the same outcome because of liquidity, fee structure, participant mix, and how each venue defines the contract. Furthermore, differing levels of information access and interpretation among traders on each platform can lead to varied assessments of the likely outcome in the Holborn and St Pancras by-election. The volume traded on each platform also plays a role; a market with higher volume generally has tighter spreads and may be more reflective of broad consensus. These variations are a natural part of a decentralized forecasting system.

Several factors could significantly impact trading activity and price movement in this market. Major campaign announcements, shifts in national political sentiment, unexpected endorsements, or significant events affecting candidate reputations could all influence traders’ perceptions. Polling data releases, while often already factored into prices, can still cause short-term volatility. Any news related to voter turnout or potential irregularities could also move the market. Monitoring these signals will be crucial for understanding the evolving forecasts for the Holborn and St Pancras by-election.