September Showdown: US Stocks and Cryptos Face Weakest Month on Record

The US stock market and cryptocurrencies are facing their weakest month on record as September begins. In August, the S&P 500 closed at a record high of 7,798.99 after rising more than 2%. Bitcoin (BTC) gained 24.95% and Ethereum (ETH) advanced 32.5%.

Historical data shows that stocks have historically performed poorly in September. The Dow Jones Industrial Average has fallen an average of 0.8% since 1950, while the S&P 500 has shed 0.7% over the same span. The Nasdaq Composite has dropped 0.9% since 1971, and the small-cap Russell 2000 has lost 0.8% since 1979.

Bank of America data dating back to 1928 show an average September S&P 500 loss of 1.17%, with the index falling in 56% of those years. According to Jeffrey Hirsch and Christopher Mistal, authors of the 2026 Stock Trader’s Almanac, this pattern is due to fund behavior after the summer break.