Recent polling across multiple firms shows incumbent Luiz Inácio Lula da Silva and Flávio Bolsonaro each hovering between 40 and 47 percent of valid votes in the October 4 first round, with all other candidates in low single digits. Brazil’s electoral rules require an absolute majority of valid ballots for an outright win, triggering a runoff otherwise. Entrenched left-right polarization, combined with vote splitting among smaller contenders, has kept both leaders well short of 50 percent in every survey released in the final week. Traders assign 99.6 percent probability to “No” because these patterns align with historical precedents in contested Brazilian presidential contests and have shown no meaningful late consolidation. An outright result would still require an unprecedented final-week surge by one frontrunner or a sudden collapse in minor-candidate support.