September has a historical reputation for being a weak month for the stock market—a statistical anomaly known as the September Effect where indices like the S&P 500 have posted negative average returns over the last century. While economists consider it more of an anecdotal pattern than a strict rule, several recurring seasonal and psychological factors tend to drive this downward pressure.
Is September the worst month for the stock market?
Often referred to as the “September Effect,” this is when the stock market tends to perform worse in September compared to any other month of the year. Investors, analysts, and economists have been scratching their heads over this for quite some time because it doesn't seem to follow typical market patterns.
September is a historically weak period for stocks, driven by summer trading return, mutual fund fiscal year-ends, and investor psychology. This tendency is known as the "September Effect".
September is historically the worst month for the stock market. Since 1928, the S&P 500 has averaged a loss of about 1.2% in September, posting negative returns more often than any other month. This seasonal trend is so well-known that it is commonly referred to as the "September Effect."
The September Effect refers to the perception that stock market returns are relatively weak during the month of September. It is considered an anomaly since it violates the assumption of efficient markets.
A stock market crash in 2026 is not guaranteed, though major warning signs like high valuations, rising oil prices, and geopolitical tensions have analysts divided.
Mondays and Fridays tend to be good days to trade stocks, while the middle of the week is less volatile. Historically, April, October, and November have been the best months to buy stocks, while September has shown the worst performance.
No, October is not historically a bad month for stocks on average, though it is famous for high volatility and a few massive, historic crashes. Opinions on online forums like r/StockMarket are mixed, with some traders anticipating a correction while others view the month as a strong buying opportunity.
While historical trends point to September and the May-to-September period as historically weaker times when prices may dip, long-term investors generally agree that the best time to buy stocks is as soon as you have money ready, rather than trying to time the market.
September is considered the worst month primarily due to the September Effect, marking the weakest historical performance for the stock market, the end of summer vacation, and the return to school and heavy traffic.
Over the last 20 years, June and September have been the only months with a negative average return. Not because they always fall, but because the losing years were severe enough to outweigh the gains. That's what makes June so difficult to trade.
December is historically one of the strongest months of the year for the stock market, primarily driven by holiday optimism and institutional portfolio adjustments. However, performance can vary depending on the index and the specific time frame you are looking at.
The Bank Panic of 1907, the Stock Market Crash of 1929, and Black Monday 1987 all happened during the month of October. Historically, September has had more down markets than October.
What is Warren Buffett saying about the stock market?
Warren Buffett says the current stock market feels expensive and is driven more by short-term gambling than true investing. He recently noted that it is tough to find good values because people prefer speculation over patience.
How much did the stock market drop on September 11, 2001?
On the first day of NYSE trading after Sept. 11, the Dow Jones fell 684 points, a 7.1% decline, setting a record at the time for the biggest loss in the exchange's history for one trading day. (This has since been eclipsed by the market reaction during the global coronavirus pandemic).
Yes, the claim is largely true. Extensive academic research across global markets shows that roughly 90% to 97% of individual day traders lose money over time.
Historically, September is the worst-performing and weakest month for the stock market, often bringing lower average returns known as the September Effect.
The middle of the week typically shows the most movement, as the pip range widens for most of the major currency pairs. Saturdays and Sundays tend to be the least favourable days for trading forex. Most traders tend to avoid trading forex during holidays and around major news events.
Our analysis of over 6,200 trading days shows that Tuesday has historically produced the highest average daily returns at 0.062%, while Friday and Monday show the lowest average returns at about 0.009% each.
Did the stock market do better under Trump or Obama?
Both Barack Obama and Donald Trump oversaw strong overall stock market gains, with Obama's eight-year total returns exceeding Trump's first term, largely because Obama took office near the bottom of the 2008 financial crisis.
Key Takeaways. The October effect is the belief that stock markets decline in October, but it's more psychological than factual. Statistics typically disprove the October effect, showing October as a positive month on average.
