U.S. stock markets closed Sept. 30 higher, ending the month on a positive note. The S&P 500 closed at 6,688.46, the Dow at 46,397.89, and the Nasdaq at 22,660.01 reuters.com. All three indices notched monthly and quarterly gains: for September, the S&P rose about 3.5% reuters.com reuters.com, and the Dow and Nasdaq each notched their largest one-month rise since 2019. This pushed the Dow to another record closing high reuters.com. Defensive sectors outperformed, while cyclical areas lagged due to shutdown risks.