September Watch: S&P 500, Dow Jones, Nasdaq Face Historically Worst Month of the Year

September Watch: S&P 500, Dow Jones, Nasdaq Face Historically Worst Month of the Year

September has long been viewed as the “Monday morning” of the stock market — unwelcome and often disappointing. Historically, the S&P 500, Dow Jones Industrial Average, and Nasdaq Composite have all delivered their weakest performance of the year during this month.

August was a month full of excitement: the S&P 500 surged past 6,500 to fresh highs, the Dow Jones hit a new record, and Europe’s Stoxx 600 logged two straight months of gains. Yet, September’s poor reputation continues to loom large over investors.

In Europe, bank stocks were the standout, rallying to their highest levels since the 2008 financial crisis. Germany’s Commerzbank led the charge, doubling its share price since the start of the year. Conversely, media stocks slumped over 8% amid AI-related disruption, with advertising giant WPP reporting a 71% drop in pre-tax profit.

On the macroeconomic front, opinions remain divided. UBS expects the bull market to hold, supported by strong corporate earnings and lower interest rates. But EY-Parthenon warned that U.S. GDP growth of 3% in Q2 2025 may be largely an “illusion,” reflecting reduced imports after front-loaded purchases to avoid tariffs.

Barclays projects both the U.S. and European economies will slow in the second half of 2025 before rebounding in 2026, navigating tariff disputes and U.S. tax reform along the way.

Key Economic Events in September

Sep 2 (Mon): U.S. markets closed for Labor Day; EU unemployment data
 

Sep 3 (Tue): EU inflation, U.S. manufacturing data
 

Sep 6 (Fri): EU GDP, U.S. nonfarm payrolls
 

Sep 8: French no-confidence referendum
 

Sep 11: ECB policy decision
 

Sep 16–17: Federal Reserve meeting
 

Sep 17: President Trump’s official U.K. visit
 

Sep 18: Bank of England policy decision