The Workers’ Party’s April 26 national congress, which approved a manifesto prioritizing President Luiz Inácio Lula da Silva’s re-election bid and directed party president Edinho Silva to build alliances around his candidacy, forms the core driver of the 85.5% implied probability for formal nomination by the August 15 deadline. Lula’s March 31 confirmation of Vice President Geraldo Alckmin as running mate, his public calls for a sharper campaign plan, and the absence of credible internal alternatives reinforce party unity ahead of the October 4, 2026 general election. Party conventions scheduled between July 20 and August 5, followed by the Superior Electoral Court’s August 1 candidate registration window, position the process as largely procedural barring unforeseen health or coalition setbacks, aligning trader consensus with these institutional steps and Lula’s incumbency advantage.