Moon phases explained
Everything the "moon vs Bitcoin" experiment is built on starts here: the lunar cycle, the two phases that matter most for the theory, and why anyone thinks they might nudge a market.
The lunar cycle: 29.5 days
The Moon doesn't produce its own light — we see the portion of it lit by the Sun. As the Moon orbits Earth, the angle between Sun, Earth and Moon changes, so the lit fraction we see grows and shrinks. One complete cycle — new moon back to new moon — is the synodic month, averaging 29.53 days.
Because that's slightly longer than a calendar month, moon phases drift across the calendar, and roughly once every 2.7 years a single month contains two full moons — the second nicknamed a "blue moon".
The eight phases
| Phase | What you see | Position |
|---|---|---|
| New moon 🌑 | Effectively invisible | Moon between Earth and Sun |
| Waxing crescent 🌒 | Thin sliver, growing | Pulling ahead of the Sun |
| First quarter 🌓 | Right half lit | 90° from the Sun |
| Waxing gibbous 🌔 | More than half, growing | Approaching opposition |
| Full moon 🌕 | Fully lit disc | Earth between Moon and Sun |
| Waning gibbous 🌖 | More than half, shrinking | Past opposition |
| Last quarter 🌗 | Left half lit | 90° the other side |
| Waning crescent 🌘 | Thin sliver, fading | Closing on the Sun again |
The two phases the theory cares about
The market lore focuses on the two extremes of illumination:
- Full moon 🌕 — maximum light, folklore's "peak energy" moment. The hypothesis: this coincides with a local top in price.
- New moon 🌑 — the dark of the moon, a symbolic reset. The hypothesis: this coincides with a local bottom.
A full moon and the next new moon are about 14.75 days apart — half a synodic month. That number matters for the analysis: it's why the tool only lets a price turning point "belong" to a moon within roughly a 14-day window, so a top can't be mis-assigned to the wrong phase.
ephem astronomy library to compute the exact instant of each full and new
moon, to the minute, across the entire price history.
Why would the Moon affect markets at all?
Honestly — there's no accepted mechanism. Proposed (and largely unproven) ideas include:
- Behavioural / mood effects. Studies have long debated whether lunar phases subtly influence human sleep and mood; if so, the argument goes, trader risk appetite might shift.
- Self-fulfilling folklore. If enough traders act on the "full moon top" idea, their behaviour could nudge price toward it regardless of any physical cause.
- Pure coincidence. With a turning point every couple of weeks and a moon every couple of weeks, some overlap is guaranteed by chance.
That last point is exactly why measurement matters. The methodology is designed to separate a real signal from random alignment — and mostly finds the pattern is weak.
Lunar phases have no established causal effect on asset prices. This is an exploration of a pattern, not a claim that the Moon moves Bitcoin.