Recent polling in Piauí shows a fragmented field for the two Senate seats, with Marcelo Castro (MDB) holding a narrow lead in voter intention surveys while Ciro Nogueira (PP) and Júlio César (PSD) remain within the margin of error. A long list of additional candidates, including Tiago Junqueira (PL) and smaller-party contenders, splits support further and sustains uncertainty over first-place positioning. Candidate registration closed in mid-August, shifting focus to formal campaigning and potential alliances ahead of the October vote. Trader pricing reflects this dispersion, with probabilities clustered tightly as no single contender has consolidated a clear advantage. Late shifts in turnout among key regional blocs or new endorsements could widen gaps before election day.