Will Flávio Bolsonaro finish in second place in the first round of the 2026 Brazilian presidential election?

Crossbook compares what two exchanges, Polymarket and Kalshi, charge for the same event, and publishes a permanent scored record of its own forecasts under published rules.

Settlement equivalence unverified. No eligible price gap is available.

SettledContract settles 5 Oct 2026Last checked 4 Oct 2026, 23:10 UTC

Bid/ask midpoint · retrieved 2026-10-04T23:10:28.055Z. Venue quote-update time is unavailable. Readings can be asynchronous.

1.0%bid 0.9% / ask 1.2%24h volume $825K · liquidity $76Kas of 4 Oct, 23:10 UTC · not refreshed recentlyView on Polymarket

Bid/ask midpoint · retrieved 2026-10-05T22:00:34.980Z. Venue quote-update time is unavailable. Readings can be asynchronous.

no two-sided marketnobody is quoting both sides, so there is no price to show24h volume $6Kas of 5 Oct, 22:00 UTC · not refreshed recentlyView the event containing this market on Kalshi

How each venue defines this

Each exchange's own settlement text, quoted as written. Where they differ, the difference is usually why the prices do.

These two contracts name settlement dates about 3 months apart. Read both terms below for why: a later date can mean a different condition, a longer deadline or an administrative delay, and only the terms say which.

Settles Oct 5, 26

A presidential election is scheduled to take place in Brazil on October 4, 2026. This market will resolve according to the listed candidate who receives the second-most valid votes in the first round of this election. The named candidates will be primarily ranked by the number of valid votes received in the specified election. If two or more candidates are tied on valid votes, ties will be broken by alphabetical order of the candidates' last names. This market will resolve to the candidate that occupies the second-highest finishing position after applying this ranking. If the result of this…

Settles Jan 1, 27

If Flávio Bolsonaro finishes in 2nd place in the first round of the 2026 Brazilian presidential election according to the certified results, then the market resolves to Yes.

Settlement equivalence unverified

A person confirmed these two markets ask the same question. Their settlement documents have not been compared, so treat the price difference as unverified rather than as a like for like gap.

Confirmed as the same question: Will Flávio Bolsonaro finish in second place in the first round of the 2026 Brazilian presidential election?

Crossbook forecast

72.0%against a market price of 68.5% at the timeNO

Logged 21 Sept 2026, 19:46 UTC · Brier 0.5184

Two independent mid-September polls agree on the ordering: Lula first, Flávio Bolsonaro second, with Bolsonaro well ahead of all other candidates — this consistent cross-pollster ordering 12-17 days before the vote is the core signal.
Downside risk is two-sided: Bolsonaro trails Lula by only ~2-3 points (within or near typical polling error in Datafolha), so a Bolsonaro first-place finish — which resolves this market NO — is a live possibility, not a tail event.
The AtlasIntel poll shows a slightly wider Lula lead (2.4 points) but also a higher combined top-two share (~86%), which compresses the room for any third candidate to overtake Bolsonaro for second.
With only 13 days to election day, the window for a late surge by a third candidate or a decisive swing is narrow, supporting staying close to the polling-implied ordering; I discount modestly for polling error, late undecideds, and campaign events.

What would change it: A late-September poll from a major house showing either Bolsonaro tied or ahead of Lula, or a third candidate within a few points of Bolsonaro, would materially move the estimate.

Settlement source

+3.5 probability points from the market at generation · med confidence · Polymarket

Base rate: In multi-candidate first-round presidential elections with a runoff (Brazil's post-1989 pattern and similar systems), the candidate running second in final pre-election polls finishes second roughly four times in five; no retrieved fact supplies this rate, so it rests on general knowledge of the class.

Formed blind at 76.0%; published at 72.0% after the reconcile step moved it toward the market. The same September Datafolha and AtlasIntel polls backing the blind estimate are public and almost certainly already priced; with no dated fact the market lacks, I shade toward the market while retaining a small premium for the consistent two-poll ordering with only 13 days left.

Chosen by hand.

Settlement

Every answer this call has been given, oldest first. Nothing is edited: a correction is a new entry beside the one it replaces.

NOsettled 5 Oct 2026, 07:30 UTC · recorded 5 Oct 2026, 15:39 UTC · read from the venuesettlement

What this call was reading

A Datafolha first-round poll conducted from September 15 to 17, 2026, recorded Lula at 39% and Flávio Bolsonaro at 36%. as of 2026-09-17 · reuters.com · within 14 days of this call
An AtlasIntel/Bloomberg first-round poll conducted from September 11 to 16, 2026, recorded Lula at 44.1% and Flávio Bolsonaro at 41.7%. as of 2026-09-16 · riotimesonline.com · within 14 days of this call
The latest reported first-round polling places Flávio Bolsonaro behind Lula and ahead of the other listed candidates. as of 2026-09-17 · riotimesonline.com · within 14 days of this call
The contest is for President of Brazil and the Tribunal Superior Eleitoral administers the presidential election. as of 2026-09-21 · tse.jus.br · within 14 days of this call
Flávio Bolsonaro is the Liberal Party presidential candidate and Luiz Inácio Lula da Silva is seeking reelection as the Workers' Party presidential candidate. as of 2026-07-25 · reuters.com

Settlement equivalence unverified. The venue readings below are not ranked as a comparable price gap.

Volume over the last 24 hours is heavy, at about $824,948 on the busier venue. At least one side of this market has no real two sided book, which means the quoted price is closer to a placeholder than to a traded level.

This market has settled. The page is kept as a record of what both venues said while the question was open, and of what Crossbook called.

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