iShares Biotechnology ETF (IBB) Seasonality
Recurring seasonal patterns for IBB — the calendar windows where iShares Biotechnology ETF has historically tended to rise or fall, with the win rate (how often it repeated) and average return for each, based on the last 10 years of price history.
IBB seasonality at a glance
Over the last 10 years, IBB's strongest seasonal window has been Jun 16 – Jul 16: it ended higher in 9 of 10 years (90% win rate) with an average return of +5.39% across a 30-day hold. On the weak side, IBB has historically declined between Feb 21 – Mar 23, falling in 9 of 10 years (average -4.44%).
In total, our analysis finds 524 recurring seasonal windows for iShares Biotechnology ETF — 336 bullish and 188 bearish. The next high-win-rate window, Sep 15 – Sep 25, opens in 4 days. These figures describe historical behaviour only — not a forecast.
IBB's upcoming & recent seasonal patterns
Holding period:10-day20-day30-dayOrdered by season — windows opening soon first, plus a couple of recently completed high-performers. Holding-period colors help you compare durations at a glance.
| Status | Seasonal window | Hold | Avg return | Win rate | This year |
|---|---|---|---|---|---|
| Completedended 9d ago | Aug 23 – Sep 2 | 10d | +1.10% | 80% | +0.11% |
| Completedended 35d ago | Jul 8 – Aug 7 | 30d | +2.01% | 80% | +0.70% |
| Upcomingin 4d | Sep 15 – Sep 25 | 10d | -1.47% | 80% | — |
| Upcomingin 6d | Sep 17 – Sep 27 | 10d | -1.51% | 80% | — |
| Upcomingin 7d | Sep 18 – Sep 28 | 10d | -1.63% | 80% | — |
| Upcomingin 8d | Sep 19 – Sep 29 | 10d | -1.94% | 80% | — |
| Upcomingin 9d | Sep 20 – Oct 20 | 30d | -2.54% | 80% | — |
Win rate = how often the pattern repeated in the same direction. Average return = the mean move across all analysed years. Past performance does not guarantee future results.
Explore IBB seasonality in full
See the seasonal curve chart, filter by win rate and return, and track upcoming windows — free during beta.
IBB seasonality FAQ
What has historically been the best month to buy IBB stock?
Based on the last 10 years of price data, IBB's strongest seasonal window starts in June: Jun 16 to Jul 16, which ended higher in 9 of 10 years (90% win rate) with an average return of +5.39%. Past seasonal patterns do not guarantee future performance.
What is IBB's strongest seasonal pattern?
IBB's highest-win-rate pattern in our data is the Jun 16 – Jul 16 window (30-day hold): up in 9 of the last 10 years with an average move of +5.39%.
When has IBB historically performed worst?
IBB's weakest recurring window has been Feb 21 to Mar 23, declining in 9 of 10 years with an average return of -4.44%.
How reliable are IBB's seasonal patterns?
Each IBB pattern is scored by its historical win rate — the share of the last 10 years it repeated in the same direction. IBB currently shows 524 recurring windows (336 bullish, 188 bearish). Seasonality describes historical tendencies only; it is not a prediction, and past performance does not guarantee future results.
What is IBB stock seasonality?
Seasonality is the tendency of a stock to perform in a similar way during the same period each year. By analysing iShares Biotechnology ETF's price history across many years, SeasonalityX identifies recurring calendar windows — exact start and end dates — where IBB has repeatedly risen (bullish) or fallen (bearish). Each pattern is scored by its win rate and average return so you can judge how reliable and how strong it has been.
Seasonality is one input among many — it works best alongside your own research and risk management. Learn more in our guide to seasonal analysis and the tutorials.