Claim check: The Santa Claus rally
“Stocks rally in the last five trading days of December and the first two of January.”
What the data says
Does not hold Not supported by the data: The Santa Claus window (last five trading days of December plus the first two of January) returned +0.05% a day on average against +0.06% for all other days in S&P 500 (n = 17 windows, 2010-01-04 to 2026-11-10; t = 0.0, likely noise). We see no sign of the claimed effect.
No effect we can tell from chance, or the opposite effect.
Who says it
Yale Hirsch coined it in the Stock Trader's Almanac (1972).
Origins are as commonly cited and were not independently verified.
How we tested it
The window is the last five trading days of December plus the first two of January. We compare the average daily return inside the window with all other days (Welch t-stat) and list the window return and hit rate for every year.
Results
| Market | Windows | Mean/day inside | Mean/day outside | Difference | Window return | Windows up | t-stat | Reading |
|---|---|---|---|---|---|---|---|---|
| S&P 500 | 17 | +0.05% | +0.06% | -0.003% | +0.3% | 71% | 0.0 (likely noise) | No effect |
Average daily return inside the window and outside it
Stability across the two halves of history
A saying that only works in one half of the history is not much of a rule. Each row shows the effect in the full history, the first half and the second half; green means the claimed effect was present.
| Market | Full history | First half | Second half |
|---|---|---|---|
| S&P 500 | 0.00% | -0.02% (57) | +0.01% (56) |
Context and cross-checks
Shown for context; not part of the verdict.
Other markets (context, not part of the verdict)
| Market | Windows | Mean/day inside | Mean/day outside | Difference | Window return | Windows up | t-stat | Reading |
|---|---|---|---|---|---|---|---|---|
| Gold | 17 | +0.26% | +0.03% | +0.234% | +1.7% | 82% | 2.6 | Clear and stable |
| Silver | 17 | +0.36% | +0.04% | +0.329% | +2.4% | 82% | 1.6 (likely noise) | Right way, likely noise |
| Commodities | 17 | +0.09% | +0.01% | +0.075% | +0.6% | 71% | 0.8 (likely noise) | Right way, likely noise |
| Agriculture | 17 | +0.03% | +0.01% | +0.026% | +0.2% | 53% | 0.4 (likely noise) | Right way, likely noise |
| EUR/USD | 17 | +0.03% | -0.01% | +0.035% | +0.2% | 65% | 0.9 (likely noise) | Right way, likely noise |
| Bitcoin | 12 | +0.33% | +0.17% | +0.163% | +2.3% | 58% | 0.5 (likely noise) | Too little data |
| Ether | 9 | +1.03% | +0.14% | +0.890% | +7.1% | 78% | 1.6 (likely noise) | Too little data |
Average daily return inside the window and outside it
The honest caveat
A seven-day window per year yields roughly 15 data points; any apparent edge is hard to separate from luck.
Descriptive statistics from historical data, before costs. Not a forecast and not investment advice.
Questions
Stocks rally in the last five trading days of December and the first two of January.
Not supported by the data: The Santa Claus window (last five trading days of December plus the first two of January) returned +0.05% a day on average against +0.06% for all other days in S&P 500 (n = 17 windows, 2010-01-04 to 2026-11-10; t = 0.0, likely noise). We see no sign of the claimed effect.
How was this claim tested?
The window is the last five trading days of December plus the first two of January. We compare the average daily return inside the window with all other days (Welch t-stat) and list the window return and hit rate for every year.
Markets used
S&P 500 · Gold · Silver · Commodities · Agriculture · EUR/USD · Bitcoin · Ether