**The Santa Catarina Senate race for the second seat remains highly fragmented eight weeks before the October 2026 vote, with trader probabilities spread across more than a dozen registered candidates.** Two seats are at stake, so voters cast first- and second-preference ballots; recent Neokemp and Mapa/Jovem Pan surveys show PL candidates Carlos Bolsonaro and Caroline de Toni frequently topping first-vote intentions (mid-20s percent range), while Esperidião Amin (PP), Décio Lima (PT), and others split the remainder. This produces a crowded second-place contest in which no single contender exceeds low-20s implied odds. Jeferson da Rocha (PRD), Afrânio Boppré (PSOL), Ana Lucia da Silveira Machado, and several others sit in the 20–22 percent band, reflecting uncertainty over which non-PL or secondary names can consolidate opposition or center-right support. The 13-candidacy field registered in mid-August, combined with still-modest name recognition for many entrants and the absence of decisive late-summer polling shifts, keeps individual probabilities compressed. Upcoming events that could widen gaps include new statewide surveys, party federation negotiations, televised debates, and any high-profile endorsements or withdrawals that consolidate second-preference flows before the final campaign stretch.