Stock Seasonality / Stock Market Seasonality
STOCK MARKET SEASONALITY
How calendar patterns appear in the stock market
Stock market seasonality looks for recurring behavior tied to months, quarters, holidays and other repeating calendar windows. The useful question is not whether a market saying is famous, but whether a measurable pattern remains consistent across historical samples.
Common forms of market seasonality
Monthly effects
Researchers compare month-by-month returns to identify historically stronger or weaker calendar periods.
Half-year effects
Periods such as November–April versus May–October are often compared as broad seasonal regimes.
Event windows
Holiday rallies, year-end behavior and recurring expiration windows can create short, highly specific research periods.
How to judge whether a pattern is robust
Strong evidence
- Positive average and median return
- Reasonable win rate
- Pattern visible across multiple lookbacks
- No dependence on one or two extreme years
Weak evidence
- Strong average but weak median
- Very small sample
- Pattern disappears after a small date shift
- Recent years behave very differently
Research market seasonality free
Use the dashboard to compare recurring calendar windows on stocks and indices.