The first-round results on October 4 produced unusually high absolute vote totals—Flávio Bolsonaro with 56.1 million and Lula with 53.9 million valid votes—amid an expanded electorate of 158.7 million. Polarization between the two runoff contenders on October 25 has driven intense mobilization by their coalitions, with most eliminated candidates’ supporters shifting toward Flávio and second-round polls showing sustained engagement. Turnout in prior Brazilian runoffs has typically exceeded first-round levels, and the combination of larger voter rolls, low abstention expectations, and concentrated support for the finalists creates conditions for at least one candidate to exceed all previous second-round totals. Traders price this outcome at 87.5% based on these structural and behavioral factors.