**Trader consensus in the Sinaloa Congress election market reflects a fragmented contest ahead of the June 6, 2027, vote that will renew the 40-seat state legislature alongside the governorship and municipalities.** Morena currently holds a working majority, but recent polling for the concurrent gubernatorial race shows its PT-PVEM coalition in a tight battle with opposition forces, marked by 30-40% undecided voters and margins often within a few points among leading profiles such as Imelda Castro (Morena coalition) and Mario Zamora (PRI). Early October developments include formalization of the Morena-PT-PVEM alliance for the gubernatura and local races, with candidate selection via surveys and negotiations due within 45 days; this coalition structure underpins elevated probabilities for PVEM and Morena. Opposition efforts to build a broader PRI-PAN-MC bloc add uncertainty, while internal party surveys and alliance talks continue to shape expectations for seat outcomes under the mixed-member system. High indecision and coalition fluidity keep probabilities clustered among the main contenders.