**Sweden’s September 13, 2026, election produced a narrow centre-left parliamentary majority of 176 seats against 173 for the outgoing Tidö parties, with the Social Democrats securing 99 seats as the largest single party.** This three-seat edge has not translated into straightforward government formation. Magdalena Andersson’s attempt to assemble an S-led cabinet involving the Greens, Centre, and Left parties collapsed by late September over irreconcilable differences, notably between the Centre Party and Left Party on cabinet participation, economic policy, and related issues. The speaker of the Riksdag has continued consultations with party leaders into early October, keeping open the possibility that Ulf Kristersson or another figure could receive the next exploratory mandate. Trader pricing across numerous S-inclusive and M-inclusive combinations remains tightly clustered because the narrow arithmetic, cross-bloc vetoes, and preference for minority or support arrangements rather than full coalitions leave multiple paths viable. Historical precedent for protracted Swedish government negotiations and the absence of any single bloc holding a clear working majority sustain this fragmentation in implied probabilities.