October is historically the most volatile month for stocks. But why? These 4 popular theories fail to hold up.
Why now
Thesis: Seasonality claim with weak support
Catalyst to watch: Actual October price action
Main risk: Overfitting to past seasonal patterns
Why it matters
October volatility is a seasonal pattern the article itself debunks, so it carries little predictive value.
Details
Although October historically has been the most volatile month of the year, you shouldn’t bet that it will continue to be in the future.
Sources
- marketwatch · 2026-09-28 20:02 UTC