The Rio de Janeiro Senate race for two seats on October 4 remains highly fragmented, with candidacy registration only recently closing and limited recent statewide polling available to separate contenders. Benedita da Silva (PT) holds a modest edge in early surveys for one seat, while PL candidates such as Carlos Jordy and Carlos Portinho, Republicanos’ Marcelo Crivella, and others including Michelly Xavier (UP), Monica Benicio (PSOL), and Luciano Mattos compete in a crowded field without a dominant frontrunner. Flávio Bolsonaro’s shift to the presidential contest opened space that has not consolidated behind any single replacement, sustaining trader consensus around even odds for leading contenders. Low voter recognition, overlapping partisan bases, and the absence of major late-campaign catalysts keep implied probabilities clustered, though fresh Datafolha results or high-profile endorsements could quickly reorder preferences before election day.