**Flávio Bolsonaro holds a commanding lead in the Brazil presidential election market following the October 4 first-round vote, where he captured 47% to incumbent Luiz Inácio Lula da Silva’s 45%, advancing both to an October 25 runoff.** No first-round loser has won the second round since Brazil’s return to democracy in 1985, and the senator’s stronger-than-expected showing—coupled with broad right-wing gains in Congress and state races—has consolidated support from eliminated conservative candidates. Recent polling and trader consensus reflect expectations of further vote migration to the Liberal Party contender in the runoff. Lula’s campaign is now emphasizing turnout in key regions, but structural and historical factors continue to underpin the wide probability gap.