Does the Full Moon Move the Nasdaq? I Tested 7 Years.
There's a story traders love to tell: the full moon makes the market crazy. Bigger swings, wild ranges, people acting on impulse. You've heard some version of it. Maybe you've felt it — a rough session, a glance at the sky, "ah, that explains it."
I wanted to know if it was real. Not vibes-real. Data-real.
So I pulled every trading day of the Micro Nasdaq (MNQ) going back to when the contract launched in 2019 — about 1,300 trading days, roughly five years — and tagged each one with its moon phase. New, first quarter, full, last quarter. Then I asked a simple question: does the range actually change with the phase?
Here's what I found. It's not what the story says.
The full moon is quieter, not wilder
If the folklore were true, full-moon days would show bigger ranges than normal. They don't. Over five years, the full moon came in about 10% below the typical day.
Here's the whole board, measured as median daily range against the all-days baseline of 231.5 points ($463):
| Moon phase | Sample | Median range | vs. baseline |
|---|---|---|---|
| New moon | 153 days | 226.2 pts / $452 | −2% |
| First quarter | 171 days | 239.0 pts / $478 | +3% |
| Full moon | 161 days | 207.8 pts / $416 | −10% |
| Last quarter | 163 days | 268.8 pts / $538 | +16% |
Read that full-moon row again. The one phase everyone points to as chaos is the one where the market was 10% calmer than usual. The wild-full-moon story isn't just unproven — the data leans the other way.
The one phase that did run wide was the last quarter (+16%) — but I'm holding that loosely. One phase poking above the noise across five years is exactly the kind of thing that can shrink back toward average once more data comes in. I'd want to watch it before I called it an edge. (Note to future me: come back and check this.)
Why I bother checking something like this
Here's the thing. I like the cyclical stuff — the moon, the seasons, the rhythm of it. I'm the person who's genuinely curious whether the sky leaves fingerprints on how people behave. Markets are just people behaving, so it's not a crazy place to look.
But curiosity and belief are two different things.
Most trading-astrology content claims the connection and never checks it. It tells you the full moon means volatility because it sounds good and nobody runs the numbers. That's not respect for the mystic — that's just being lazy with it.
And most quant content has the opposite problem: it's so allergic to anything unconventional that it never looks in the interesting places at all. It would never even ask the moon question.
I do both. I look where it's interesting, and then I count. When the numbers say "real," I use it. When they say "myth," I say myth — out loud, even when the myth was more fun.
On the Nasdaq, the full moon is basically noise. That's the honest answer.
What the data pointed at instead
While I had seven years tagged and sliced, the market was happy to show me what does move it — and none of it needed the cosmos:
- Options-expiration days squeeze the range. On the big quarterly expirations, the Nasdaq's range shrank by nearly half. The market pins and grinds instead of running. That's a real, usable read.
- The turn of the month runs wide — but chops. The first trading days of a month move more than normal, but they don't pick a direction. Wide and two-sided. Trade them like a range, not a trend.
- Mondays lean up. Not dramatically, but consistently more up than down.
These aren't secrets from the stars. They're patterns in human behavior — fund flows, options mechanics, how people position around the calendar. Which is exactly my point: the edges were hiding in the ordinary places, while the moon got all the attention for nothing.
The takeaway (and the whole philosophy in one line)
Don't trade the full moon expecting fireworks. On the Nasdaq, it doesn't deliver them.
But more than that: don't trade any story you haven't checked. The market doesn't care what sounds good. Your edge doesn't come from the belief — it comes from being willing to test the belief and accept whatever falls out.
I went looking in a "mystic" place with a quant's tools, and the honest result was no effect. That's not a disappointment. That's the method working. Next time it might say the opposite, and then I'll have something real.
Sharpen your edge by telling yourself the truth. Even about the moon.
— 23HT
How this was done: ~1,300 daily MNQ bars from the contract's 2019 launch through mid-2024, each tagged with its moon phase computed from actual astronomical data, then compared by median daily range against the all-days baseline. Same method, more factors, coming in future posts.