Bitcoin in September: seasonality and history
Since 2010, Bitcoin has risen in September in 47% of years (8 of 17), with an average return of −2.72% and a median of −1.78%. That makes September its #12 month of 12.
Average−2.72%
Years up47%
Best year2012 · +22.66%
Worst year2011 · −37.27%
The seasonal path through September
Cumulative sum of each day's average return through September, all years since 2010.
| Strongest days | Avg | Up |
|---|---|---|
| Sep 11 | +1.93% | 71% |
| Sep 18 | +1.86% | 76% |
| Sep 30 | +1.03% | 47% |
| Weakest days | Avg | Up |
|---|---|---|
| Sep 21 | −1.52% | 29% |
| Sep 8 | −1.39% | 29% |
| Sep 24 | −1.09% | 35% |
September in recent years
| Year | Bitcoin in September |
|---|---|
| 2026 | +6.37% |
| 2025 | +5.38% |
| 2024 | +7.39% |
| 2023 | +4.00% |
| 2022 | −3.08% |
| 2021 | −7.16% |
| 2020 | −7.67% |
| 2019 | −13.88% |
| 2018 | −5.85% |
| 2017 | −7.75% |
Questions
Is September a bad month for Bitcoin?
On average, yes: −2.72% since 2010, rising in 47% of years. But the range is wide, from −37.27% in 2011 to +22.66% in 2012, so an average is a tendency, not a forecast.
What are the strongest days in September?
Sep 11 (+1.93%, up 71% of years), Sep 18 (+1.86%, up 76% of years), Sep 30 (+1.03%, up 47% of years).