The S&P 500 Fell in Both September and October for Only the 17th Time Since 1950. Here's What Usually Followed.

The S&P 500 experienced back-to-back monthly losses in September and October 2026 (down ~0.5% and ~0.9% respectively), marking only the 17th occurrence since 1950. Historical analysis shows that in 12 of 16 past cases, the index gained in November-December with a median gain of 3.7%, and was higher 12 months later in 14 of 16 cases. However, the author notes that this pattern is similar to normal years and the current high valuation (CAPE ratio of ~41) warrants modest expectations for buy-and-hold investors.