Social Democrats lead recent opinion polls ahead of the September 13, 2026, Swedish parliamentary election, positioning them as the likely anchor of the next government under proportional representation rules that require 4% of the national vote for Riksdag seats. The incumbent Tidö arrangement—a minority coalition of Moderates, Christian Democrats, and Liberals backed by Sweden Democrats—trails in surveys, with left-leaning parties showing stronger combined support. Traders price the Social Democrats at high probability for inclusion based on consistent polling leads and historical patterns of the largest party forming the core of government. Coalition negotiations after election night remain fluid, as smaller parties like the Greens, Left, and Centre test thresholds that could determine final participation or external support arrangements. No major late-breaking events have altered the polling trajectory in recent weeks.