Investors head into a part of the calendar that tends to be upbeat for US stocks, but that seasonal strength is under threat from a number of challenges, including a surge in bond yields and the market's apparent dependence on massive AI spending.
As the fourth quarter kicks off, the stock market is already on pace for a solid year. The benchmark S&P 500 as of Friday had gained nearly 13% in 2026, and sat about 1% below its mid-August record high.
