S&P 500 Down 1.75% in September Through Sept. 20

S&P 500 fell 1.75% in September through Sept. 20, with Nasdaq down 1.5%, Yahoo Finance reported. September averages a 1.1% loss since 1928 and ranks as the worst calendar month. Context for savers: index was still up 12.3% in 2026. I’d treat seasonal softness as noise against that cushion, not a verdict on the year.