Closest Senate Race?
PM $120.1K · K 3.40M contracts
2
55
Closest Senate Race?
PM $120.1K · K 3.40M contracts
2
55
Polymarket vs Kalshi
Snapshot from
As of Nov 6, 2026, 12:00 PM UTC, Mississippi is priced at 96.5% on Polymarket and 95.5% on Kalshi.
| Outcome (Yes price) | Polymarket | Kalshi | Gap |
|---|---|---|---|
| MississippiSame question, fine print differs | 96.5% | 95.5% | 1.0 pts |
| AlaskaSame question, fine print differs | 3.1% | 4.3% | 1.1 pts |
| LouisianaSame question, fine print differs | 0.5% | 1.5% | 0.9 pts |
| KansasSame question, fine print differs | 0.5% | 0.5% | 0.0 pts |
| MichiganSame question, fine print differs | 0.5% | <0.1% | 0.5 pts |
| MontanaSame question, fine print differs | 0.5% | 0.5% | 0.0 pts |
| South CarolinaSame question, fine print differs | 0.5% | 0.5% | 0.0 pts |
| South DakotaSame question, fine print differs | 0.5% | 0.5% | 0.0 pts |
Yes prices for outcomes an automated review found to ask the same question on both platforms. They are not order quotes; check each platform's rules, fees and live prices before trading.
AI Analysis
Trader mode: Market mechanics, assumptions and risks
PM $120.1K · K 3.40M contracts
Reported volume · provider units
55
Saved contracts
18
Same-question pairs
Source snapshot: Nov 6, 2026, 12:00 PM UTC
About This Event
The 2026 midterm elections are scheduled to be held on November 3, 2026. This market will resolve according to the US Senate race which has the smallest margin of victory. For the purpose of this market, the “margin of victory” is defined as the absolute difference between the percentages of valid votes received by the first- and second-place candidates. Percentages of the valid votes received by each candidate will be determined by dividing the total number of valid votes each of the top two candidates receives by the sum of all valid votes cast in the election. For elections that include runoffs, ranked-choice, or other multi-round elections, the relevant margin of victory will be that of the round in which the winner is determined. If two state margins of victory are identical, this market will resolve to the tied state whose name comes first alphabetically. This market will consider all regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026. The resolution source for this market will be a compilation of all of the relevant state election authorities responsible for certifying statewide elections, however, a consensus of credible reporting may also be used.
This analysis is awaiting a background update, so its prices may be older than the odds above.
Snapshot observed 2026-10-24T00:00:06.197Z. This analysis describes that snapshot and is not a live news update.
What the contract measures
The Polymarket event "Closest Senate Race?" resolves according to the US Senate race with the smallest margin of victory. The margin is the absolute difference between the percentages of valid votes received by the first- and second-place candidates, and each percentage is calculated against the sum of all valid votes cast in the election [1]. For runoff, ranked-choice, or other multi-round elections, the margin is taken from the round that determines the winner [1]. If two state margins are identical, the market resolves to the tied state whose name comes first alphabetically [1].
The contract covers regular and special Senate elections scheduled for November 2026 that determine representation in the 120th Congress, as of October 31, 2026 [1]. The stated resolution source is a compilation of state election authorities that certify statewide elections, though a consensus of credible reporting may also be used [1]. The listed end time is 2026-11-04T04:59:00.000Z, and the provider status is active [1]. The event text says the election is scheduled for November 3, 2026 [1]. The listed end time is a provider field and does not by itself state when results will be certified.
Reading the snapshot
The market data were observed at 2026-10-24T00:00:06.197Z and retrieved at 2026-10-24T02:35:23.605Z. These are past observation times, not live prices. Each state is a separate yes or no contract. Among the 12 included markets, the highest Yes snapshot prices were Kansas at 0.1545, Iowa at 0.153, and Texas at 0.135 [1]. The lowest included Yes prices were Louisiana at 0.044 and South Dakota at 0.045 [1].
These figures are not verified probabilities or executable quotes. The sample covers 12 of 35 markets for this provider event, and the selection rule orders markets by Yes price, then by volume [1]. The 23 markets not shown have no prices in this evidence, so they cannot be compared with the included ones. The contracts are also different questions, so their prices should not be combined into a single figure.
What remains uncertain
The evidence does not explain why any price was at its level at observation time, and it does not report trader counts, liquidity, or news. Volume is not included in the discussion above and would not indicate liquidity or participation even if it were. The contract's resolution depends on certified state results and the rules described above, which the snapshot cannot confirm. Differences between state contracts with similar wording should be read only as differences in the observed snapshot prices, not as evidence that one outcome is more likely than another.
References
- Polymarket: Closest Senate Race?. Provider data observed 2026-10-24T00:00:06.197Z.
AI-generated analysis based on market data. Not financial advice.
Saved Oct 24, 2026 UTCThis saved content is awaiting a background update. It may contain outdated claims; use the dated market data and provider rules for the latest available information.
Overview
This PredictPedia contract asks which 2026 U.S. Senate race will have the smallest margin of victory. The contract rules define the margin as the absolute difference between the percentages of valid votes received by the first- and second-place candidates, with each percentage calculated by dividing a candidate's valid votes by the sum of all valid votes cast in the election [1]. The rules state that the 2026 midterm elections are scheduled for November 3, 2026 [1]. The contract covers all regular and special Senate elections that determine representation in the 120th Congress and are scheduled for November 2026 as of October 31, 2026 [1]. For elections with runoffs, ranked-choice voting, or other multi-round formats, the margin is measured in the round where the winner is determined [1]. If two states have identical margins, the contract resolves to the tied state whose name comes first alphabetically [1]. The rules name a compilation of state election authorities responsible for certifying statewide results as the resolution source, and allow a consensus of credible reporting to be used [1]. The listed end time for the contract is 2026-11-04T04:59:00Z [1]. That date is the contract's listed closing time, not an announced date for results, and the contract's rules do not state when any race will be certified. The market sample shown with this article is partial. It includes 12 of 35 markets from one provider event, selected by highest Yes price and then volume. Yes prices in the sample range from about 4.4 to 15.5 cents, and the highest-priced included markets are Kansas at 0.1545, Iowa at 0.153, and Texas at 0.135 [1]. These are snapshot prices, not executable quotes or verified probabilities, and volume reflects trading activity rather than liquidity or the number of traders. Markets outside the sample are not shown, so their prices should not be inferred from the sample.
Historical Context
The supplied background sources cover two 2024 Senate elections, held on November 5, 2024. In Wisconsin, incumbent Democratic Senator Tammy Baldwin won a third term by a 0.85% margin over Eric Hovde [2]. In Vermont, incumbent independent Senator Bernie Sanders won a fourth term over Gerald Malloy after primaries held on August 13, 2024 [3]. These are historical examples of recent Senate results. The sources do not connect them to the 2026 contract's rules or to current 2026 race results.
Why It Matters
The contract measures how closely contested the most competitive 2026 Senate race will be, using a specific formula based on the gap between the top two candidates' shares of valid votes [1]. Because the margin is based on percentage shares rather than raw vote totals, a race is compared on the same scale regardless of population size [1]. The contract also specifies how multi-round elections are handled and how ties are broken [1], which determines how a result would be classified. The 2024 Wisconsin result shows a margin under one percentage point in a single race [2], which illustrates the scale of margin the contract measures. The contract does not say whether any 2026 race will fall into that range. Current prices for individual state markets are snapshots taken at an earlier observation time and should be read as market sentiment at that moment, not as a forecast [1].
Snapshot context
The latest published provider snapshot for this topic was observed on 2026-10-24 at 00:00 UTC. It contains listings from Polymarket. Market descriptions and listed closing times define the contracts; they do not establish that the real-world outcome has occurred. This article does not include a separately verified news update. [1]
Frequently Asked Questions
How is the margin of victory calculated in this contract?
The margin is the absolute difference between the percentages of valid votes received by the first- and second-place candidates. Each percentage is the candidate's valid votes divided by the total valid votes cast in the election [1].
What happens if two Senate races have the same margin?
The contract resolves to the tied state whose name comes first alphabetically [1].
Which elections does the contract include?
It includes all regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026 [1].
AI-written background. References identify the evidence used; Wikipedia links under Learn More are additional reading. Prices and provider rules are dated snapshots. This is not financial advice.
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Price gaps of 2 pp+
0
Same-question pairs
18
Largest saved gap: 1.1 percentage points.
Price differences do not establish arbitrage. Check each pair's review, current order prices, fees and settlement rules.
