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2,984,028,936

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$1,857,846,526

408,774

Markets across

40,345

events

MATCHED EVENTS:

4,373

PLATFORM COVERAGE:

5

Polymarket:

37%

VS.

Kalshi:

63%

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Next Brazil Senate Election: Most Seats Won
polymarket
kalshi

Which party will win most Senate seats?

Volume:
$356,089

Liberal Party

all

2 markets

Kalshi

Polymarket

consensus

News

Positive

Negative

Neutral

Hover marker for details

Vol.

·

Resolved Oct 5, 2026

Closed: Oct 5, 11:06 AM EST

kalshi

Kalshi

View
Join Kalshi and score $25 for your first trade.
Outcome
Trade
Chance %
Price
Spread
Liquidity
Volume
24h
7d
Open Interest
Ends in
Result
kalshi

Liberal Party

View
100%
4%
Yes 100¢No 0¢
—
N/A
$18,410
N/A
N/A
$8,725
Settled
Yes
polymarket

PL

View
100%
4%
Yes 100¢No 0.1¢
—
N/A
$269,387
N/A
N/A
N/A
Settled
Yes
polymarket

MDB

View
0%
Yes 0.1¢No 100¢
—
N/A
$10,146
N/A
N/A
N/A
Settled
No
kalshi

Brazilian Democratic Movement

View
0%
9%
Yes 0¢No 100¢
—
N/A
$2,634
N/A
N/A
$2,162
Settled
No
polymarket

PDT

View
0%
Yes 0.1¢No 100¢
—
N/A
$9,164
N/A
N/A
N/A
Settled
No
polymarket

PSB

View
0%
Yes 0.1¢No 100¢
—
N/A
$8,810
N/A
N/A
N/A
Settled
No
polymarket

PODEMOS

View
0%
Yes 0.1¢No 100¢
—
N/A
$5,024
N/A
N/A
N/A
Settled
No
polymarket

PT

View
0%
1%
Yes 0.1¢No 100¢
—
N/A
$4,606
N/A
N/A
N/A
Settled
No
polymarket

REPUBLICANOS

View
0%
Yes 0.1¢No 100¢
—
N/A
$4,355
N/A
N/A
N/A
Settled
No
polymarket

UNIÃO

View
0%
1%
Yes 0.1¢No 100¢
—
N/A
$4,131
N/A
N/A
N/A
Settled
No
polymarket

NOVO

View
0%
Yes 0.1¢No 100¢
—
N/A
$4,062
N/A
N/A
N/A
Settled
No
kalshi

Brazil Union

View
0%
3%
Yes 0¢No 100¢
—
N/A
$3,864
N/A
N/A
$2,708
Settled
No
polymarket

PSDB

View
0%
Yes 0.1¢No 100¢
—
N/A
$3,564
N/A
N/A
N/A
Settled
No
polymarket

PP

View
0%
Yes 0.1¢No 100¢
—
N/A
$3,509
N/A
N/A
N/A
Settled
No
polymarket

PSD

View
0%
Yes 0.1¢No 100¢
—
N/A
$3,407
N/A
N/A
N/A
Settled
No
kalshi

Workers' Party

View
0%
Yes 0¢No 100¢
—
N/A
$647
N/A
N/A
$408
Settled
No
kalshi

Social Democratic Party

View
0%
3%
Yes 0¢No 100¢
—
N/A
$368
N/A
N/A
$252
Settled
No
polymarket

Other

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

F

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

G

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

M

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

N

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

C

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

D

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
polymarket

H

View
N/A
N/A
—
N/A
N/A
N/A
N/A
N/A
Settled
No
Total markets: 25 of 44

Intro

This market tracks which political party will win the most seats in the 2026 Brazilian Senate election, an election that will determine control of two-thirds of the 81 Senate seats. Currently, the consensus probability favors the Liberal Party winning, at 95.0%. This forecast aggregates data from Polymarket and Kalshi, and will resolve according to official results from the Brazilian Superior Electoral Court (TSE) (www.tse.jus.br/eleicoes/resultados-eleicoes). The Social Democratic Party currently holds a 2.7% probability. Keep an eye on the election results as they are reported on October 26, 2026, to see which party secures the majority.

PredictionHero - Resolution Divergence Alerts (RDA)

Unified Resolution Criteria (Consistent across platforms)

Both Polymarket and Kalshi markets resolve to the same event: determining the party with the most seats in the 2026 Brazilian Senate election, using the official results from the TSE.Primary resolution logic: Brazilian Superior Electoral Court (TSE) (www.tse.jus.br/eleicoes/resultados-eleicoes)

Core resolution logic:

  • The market resolves to the political party that wins the greatest number of seats in the 2026 Brazilian Senate election.
  • Official results from the Brazilian Superior Electoral Court (TSE) are the definitive source for determining the winner.

Edge cases & clarifications:

  • Tie: In the event of a tie for the most seats, the market will resolve based on the official results as reported by the TSE, even if the tie isn't explicitly broken in their reporting. The platform will likely resolve to the party listed first alphabetically in the official results.
  • Delayed Results: Polymarket specifies resolution to 'Other' if results aren't available by June 30, 2027. Kalshi does not explicitly address this scenario, but the TSE is the ultimate source, so a significant delay would likely lead to a delayed resolution on both platforms.
Timing: Resolution will occur after the official results of the 2026 Brazilian Senate election are published by the TSE, with a maximum resolution date of June 30, 2027, for Polymarket.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

The next federal Senate election is scheduled to take place in Brazil on October 4, 2026, in which two-thirds of the Senate’s 81 seats will be contested. This market will resolve according to the political party that wins the greatest number of seats in the next Brazilian Senate election. Only seats contested in the next Brazilian Senate election will be considered. In the event of a tie between multiple parties for the most seats won, this market will resolve in favor of the party whose listed abbreviation appears first in alphabetical order. This market's resolution will be based solely on the number of seats won by the named party in the Brazilian Senate, not by any federation or coalition it may be a part of. If the result of this election isn't known definitively by June 30, 2027, 11:59 PM ET, the market will resolve to "Other". This market will resolve based on the result of the election, as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the Brazilian government, specifically the Superior Electoral Court (Tribunal Superior Eleitoral, TSE) (e.g., www.tse.jus.br/eleicoes/resultados-eleicoes).

Kalshi

The winner is the party or formal pre-election coalition that wins the most seats in the Senate election, even if they do not form the government. Only seats actually contested in the specified election count. If there is a tie for the most seats, the winner is the party that enters government; if that doesn't resolve the tie, the winner is the party with the higher share of the vote. If a formal pre-election coalition wins the most seats, the contract for that coalition resolves to Yes, while contracts for its individual member parties resolve to No. Resolution is based on official certification by the relevant electoral authority. If results are contested, the final certified outcome by the appropriate electoral authority or highest court with jurisdiction prevails. If an election is postponed, the contract remains open until the new date, for a maximum of two years.

Frequently asked questions

Prediction market odds often provide a different perspective than traditional polling averages. While polls capture stated preferences, this market reflects what people are willing to *bet* on, which can reveal more about true beliefs and expectations. Polling data can be susceptible to biases, such as social desirability bias, while the financial incentive in prediction markets encourages more honest and accurate predictions. However, it’s important to remember that both prediction markets and polls have limitations, and neither is a perfect predictor of the future. This market offers a real-time assessment of probabilities as perceived by informed traders.

Several signals and events could significantly impact this market. Major political endorsements, shifts in public opinion revealed by new polling data, and significant economic developments in Brazil could all influence trader sentiment. Unexpected scandals involving candidates or parties, changes in campaign finance regulations, or even unforeseen geopolitical events could also move the market. Any news that alters the perceived likelihood of a particular party winning seats in the Brazil Senate election has the potential to shift the odds on Polymarket and Kalshi.