Nasdaq Composite in September: seasonality and history
Since 1971, the Nasdaq has risen in September in 54% of years (30 of 56), with an average return of −0.72% and a median of +0.35%. That makes September its #12 month of 12.
Average−0.72%
Years up54%
Best year1998 · +12.98%
Worst year2001 · −16.98%
The seasonal path through September
Cumulative sum of each day's average return through September, all years since 1971.
| Strongest days | Avg | Up |
|---|---|---|
| Sep 19 | +0.37% | 57% |
| Sep 11 | +0.29% | 64% |
| Sep 2 | +0.27% | 69% |
| Weakest days | Avg | Up |
|---|---|---|
| Sep 29 | −0.36% | 38% |
| Sep 21 | −0.31% | 40% |
| Sep 17 | −0.31% | 48% |
September in recent years
| Year | Nasdaq in September |
|---|---|
| 2026 | +1.86% |
| 2025 | +5.61% |
| 2024 | +2.68% |
| 2023 | −5.81% |
| 2022 | −10.50% |
| 2021 | −5.31% |
| 2020 | −5.16% |
| 2019 | +0.46% |
| 2018 | −0.78% |
| 2017 | +1.05% |
Questions
Is September a bad month for the Nasdaq?
On average, yes: −0.72% since 1971, rising in 54% of years. But the range is wide, from −16.98% in 2001 to +12.98% in 1998, so an average is a tendency, not a forecast.
What are the strongest days in September?
Sep 19 (+0.37%, up 57% of years), Sep 11 (+0.29%, up 64% of years), Sep 2 (+0.27%, up 69% of years).