Tracking the moon-phase anomaly in stock-market returns · 1928–2026
Each day is shaded by the historical cumulative return of its lunar phase (1928–2026 dataset). Hover a day for details.
Simulated on the baked 1928–2026 dataset — a contested anomaly, not investment advice.
In behavioral finance, the lunar effect proposes that the moon's phase subtly shifts collective investor mood. Around the new moon, sentiment runs brighter and buying pressure tends to lift returns; around the full moon, mood sags and returns historically soften.
The race above replays a dollar invested in the U.S. market since 1928 — but only ever held while the moon sat in one specific phase. Nearly a century on, the gap is stark: capital that rode only the new moon compounded into roughly 12×, while the waxing-crescent and full-moon windows barely moved.
The lunar effect is a contested anomaly. Most rigorous studies find the signal small, unstable across decades, and easily erased by trading costs. This page is a visualization for curiosity — not investment advice.