**Trader consensus centers on 78-80% turnout for Brazil’s October 25 presidential runoff, reflecting the 78.92% first-round participation recorded on October 4.** Abstention reached 21.08%—the highest first-round rate since 1998 and continuing a five-election rise—leaving more than 33 million eligible voters at home amid an aging electorate and signs of disengagement. The tight contest between incumbent Luiz Inácio Lula da Silva and Flávio Bolsonaro, with neither securing a first-round majority, has produced a polarized campaign that typically sustains or slightly lifts participation through targeted mobilization. Historical runoff patterns and the narrow first-round gap support expectations that turnout will remain near recent levels rather than rebound sharply or decline further before the October 25 vote.