Humberto Costa secured first place in Pernambuco's Senate election with roughly 27% of valid votes, ahead of Marília Arraes at 25% and Mendonça Filho at 19%, based on full tabulation from October 4. As the incumbent PT senator seeking a third term, Costa benefited from his established record, including prior service as Health Minister and recent sponsorship of patient rights legislation, alongside a coordinated campaign within the Frente Popular alliance that paired his candidacy with Arraes. Pre-election polling showed a tight contest that tightened further in his favor near voting day, reflecting voter consolidation around the PT-PDT ticket aligned with President Lula. The result aligns with trader consensus reflected in current market pricing. Late legal challenges or recount procedures remain the primary, though low-probability, factors that could still affect formal certification.