Recent polling from Datafolha and Quaest shows Marília Arraes (PDT) leading for one Pernambuco Senate seat, while Humberto Costa (PT), Mendonça Filho (PL), and Eduardo da Fonte (PP) remain closely bunched for second amid high undecided and blank/null shares near 30%. Humberto Costa, the incumbent seeking re-election on a slate aligned with João Campos, holds a narrow edge in most surveys, though Mendonça Filho and da Fonte—backed by Governor Raquel Lyra’s coalition—trail within margins of error. These stable patterns, with minimal shifts since mid-September, underpin trader pricing that treats the second-place outcome as highly competitive ahead of the October 4 first round.