Will Flávio Bolsonaro win the second round of the 2026 Brazilian presidential election by 4–8%?

ResolutionResolved NO

YES payout0¢

NO payout100¢

VenuePolymarket

Conviction at publication

Realized · held to resolution+56%$100 paper stake

Polymarket36¢ → 0¢

Oct 20 forecast

A Flávio Bolsonaro runoff win by 4–8 percentage points remains a meaningful underdog because most national polls place Bolsonaro's lead below 3 points.

In the October 4 first round, Flávio Bolsonaro led Luiz Inácio Lula da Silva by 1.87 percentage points (47.03% to 45.16%). Since then, national second-round polling has largely reinforced this close alignment. High-profile surveys from AtlasIntel, Datafolha, BTG/Nexus, and Ipespe show Bolsonaro leading by margins ranging from 0.6 to 2.4 percentage points, while one poll shows Lula ahead. However, several other institutes, including Real Time Big Data, PoderData, and Gerp, have recorded Bolsonaro at 52% to 48%, landing precisely on the 4.0 percentage point lower boundary of this bracket, with DataTrends showing a 6.2-point margin. Prediction markets currently price this specific margin as an underdog outcome, reflecting consensus polling that concentrates the race in a tighter band. While an absolute victory of 4 to 8 points remains plausible if late momentum breaks toward Bolsonaro, the density of polling data makes a narrower victory more probable overall.

Points to NO

The majority of national polling institutes show a margin tighter than 4 percentage points.
Surveys from AtlasIntel, Datafolha, BTG/Nexus, Veritá, and Ipespe published between October 15 and 20, 2026, report Bolsonaro leading by between 0.6 and 2.4 percentage points.
The baseline first-round vote margin was under 2 percentage points.
In the official October 4 first round, Bolsonaro received 47.03% of valid votes versus 45.16% for Lula, an absolute difference of 1.87 points.
Isolated polling continues to show Lula competitive or slightly ahead in valid votes.
The Vox Brasil poll conducted October 15–17, 2026, showed Lula leading Bolsonaro 51% to 49% in valid votes.

Points to YES

Multiple reputable surveys place Bolsonaro's valid vote lead directly at the 4 percentage point threshold.
Polls by Real Time Big Data, PoderData/Aya, and Gerp published between October 18 and 20, 2026, all showed Bolsonaro at 52% to Lula's 48% in valid votes.

Research and information only. Not financial advice or a recommendation to trade. Markets involve risk, including loss of capital. Review venue rules and eligibility before trading.