Flávio Bolsonaro’s unexpected first-round lead of roughly 47% to Lula da Silva’s 45% on October 4 has consolidated right-wing support ahead of the October 25 runoff, driving trader consensus reflected in the 83.3% implied probability for the Liberal Party senator. With other conservative candidates eliminated, analysts note likely migration of those votes to Bolsonaro, alongside regional strengths in the South and Southeast and backing from evangelical voters. Lula, at 80 and seeking a fourth nonconsecutive term, faces headwinds including economic dissatisfaction and lower approval ratings. Recent runoff polls remain close within margins of error, yet prediction markets price in momentum for Bolsonaro and structural advantages in vote consolidation. Late developments such as debates or turnout shifts could still influence the outcome.