Flávio Bolsonaro wins the most votes in the first round of the 2026 Brazilian presidential election.
Brazil holds the first round of its presidential race on October 4, 2026, requiring a plurality of valid votes to win the round.
Across 6 frontier models answering independently, the panel has all but ruled it out: the median is 6%.
They broadly agree, 21 points between GPT at 24% and Claude at 3%.
Money disagrees. The market sits at 33%, so the models are 27 points less confident than people with cash on the outcome — one of the wider gaps in the archive.
Nothing is settled until 5 Oct 2026, when the outcome is checked against sources and every number above gets a permanent score.
- AI edge
- -27 pts
- Moved this week
- +3 pts
- Volume
- $246K
The models are sharply less confident than traders risking real money: 6% against 33%.
What each one said
-
GPTOpenAI
It turns on whether Bolsonaro’s inherited right-wing vote consolidates behind Flávio rather than a stronger anti-Lula alternative.
- Election-day polling and turnout on October 4 will decide it; official TSE vote tabulation should establish the leader within days.
- Brazil’s 2022 first round was effectively a Lula-versus-Bolsonaro duopoly, but a new Bolsonaro nominee faces weaker personal recognition.
- A late endorsement or withdrawal by major right-wing rivals, especially Tarcísio de Freitas, would materially raise Flávio’s chances.
24% -
QwenAlibaba
Flávio Bolsonaro is not the leading right-wing candidate; Lula or the main opposition figure will almost certainly outpoll him.
- Flávio Bolsonaro has not been the frontrunner of the right; Tarcísio de Freitas or another candidate has been the primary opposition figure in most polling scenarios.
- Lula da Silva, if running, consistently leads or is competitive in first-round polling against any Bolsonaro family member, and Flávio's personal approval ratings trail…
- Even in a scenario where Jair Bolsonaro is ineligible and endorses Flávio, the endorsement transfer has historically been incomplete, and other right-wing candidates…
12% -
GrokxAI
Flávio trails far behind Lula and Tarcísio in final polls three days out.
- Lula (incumbent) and Tarcísio de Freitas hold 30-plus percent each in late September TSE-tracked polls; Flávio sits in single digits.
- First-round plurality requires only the most valid votes, yet no late surge or withdrawal has closed a 20-point gap historically in Brazil.
- A last-minute Bolsonaro-family consolidation or polling error of 2018 scale would be needed to reverse the ranking.
8% -
GeminiGoogle
Flávio Bolsonaro is far behind Tarcísio de Freitas and Michelle Bolsonaro as the standard-bearer for the right against Lula in 2026.
- Jair Bolsonaro's ineligibility makes Tarcísio or Michelle the preferred right-wing picks; Flávio lacks broad national appeal.
- Incumbent Lula commands a solid 35-45% base, meaning whoever leads round one must unite the non-left entirely.
- Polling consistently places Flávio far behind viable alternatives, making even a plurality candidacy nomination highly improbable.
4% -
ClaudeAnthropic
Flávio Bolsonaro isn't the Bolsonarista frontrunner; Jair/Tarcísio-aligned figures or Lula poll far higher.
- Polling through 2026 has shown Flávio far behind figures like Tarcísio de Freitas or an incumbent/Lula-aligned candidate.
- Flávio is a senator with regional strength in Rio but lacks national polling lead needed to top a crowded first round.
- A late consolidation of the Bolsonarista base behind him could change this, but no evidence points that way as of Oct 2026.
3% -
DeepSeekDeepSeek
Flávio Bolsonaro's polling ceiling makes a first-round plurality essentially unreachable with Lula dominating.
- AtlasIntel/Quaest polls show him at roughly 15–20% versus Lula near 40%, far short of the ~35% needed to top the field.
- His father Jair remains barred until 2030; without transferable coattails Flávio cannot consolidate the right against Tarcísio de Freitas splitting it.
- The only path would require an unprecedented late surge plus simultaneous collapse of both Lula and centrist rivals within days.
3%
6 of 6 models answered · 21 points between the highest and lowest. None was shown the market price.
Resolution criteria
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 most valid votes in the first round of this election. Candidates will be primarily ranked by order of valid votes won. If two or more candidates are tied for any position, ties will be broken by alphabetical order of the candidates’ listed full names as they appear in this market. This market will resolve to the candidate that occupies the highest finishing position after applying this ranking. 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., https://dadosabertos.tse.jus.br/).
Question sourced from Polymarket on 1 Oct 2026. Forecast by google/gemini-3.8-flash, anthropic/claude-sonnet-5, openai/gpt-5.6-terra, x-ai/grok-4.6, deepseek/deepseek-v4.1-flash, qwen/qwen3.8-max-0902 via OpenRouter.