Amphstar Pharmaceuticals, Inc. (AMPH) Seasonality
Recurring seasonal patterns for AMPH — the calendar windows where Amphstar Pharmaceuticals, Inc. 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.
AMPH seasonality at a glance
Over the last 10 years, AMPH's strongest seasonal window has been May 7 – May 27: it ended higher in 8 of 10 years (80% win rate) with an average return of +8.09% across a 20-day hold. On the weak side, AMPH has historically declined between Aug 31 – Sep 10, falling in 9 of 10 years (average -4.87%).
In total, our analysis finds 775 recurring seasonal windows for Amphstar Pharmaceuticals, Inc. — 499 bullish and 276 bearish. The next high-win-rate window, Aug 10 – Aug 30, opens in 14 days. These figures describe historical behaviour only — not a forecast.
AMPH'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 56d ago | May 12 – Jun 1 | 20d | +5.11% | 80% | +5.26% |
| Completedended 65d ago | May 13 – May 23 | 10d | +3.26% | 80% | +0.49% |
| Upcomingin 14d | Aug 10 – Aug 30 | 20d | +5.70% | 80% | — |
| Upcomingin 15d | Aug 11 – Aug 21 | 10d | +3.92% | 80% | — |
| Upcomingin 22d | Aug 18 – Aug 28 | 10d | +1.25% | 80% | — |
| Upcomingin 24d | Aug 20 – Sep 9 | 20d | -3.32% | 80% | — |
| Upcomingin 25d | Aug 21 – Sep 10 | 20d | -4.14% | 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 AMPH seasonality in full
See the seasonal curve chart, filter by win rate and return, and track upcoming windows — free during beta.
AMPH seasonality FAQ
What has historically been the best month to buy AMPH stock?
Based on the last 10 years of price data, AMPH's strongest seasonal window starts in May: May 7 to May 27, which ended higher in 8 of 10 years (80% win rate) with an average return of +8.09%. Past seasonal patterns do not guarantee future performance.
What is AMPH's strongest seasonal pattern?
AMPH's highest-win-rate pattern in our data is the May 7 – May 27 window (20-day hold): up in 8 of the last 10 years with an average move of +8.09%.
When has AMPH historically performed worst?
AMPH's weakest recurring window has been Aug 31 to Sep 10, declining in 9 of 10 years with an average return of -4.87%.
How reliable are AMPH's seasonal patterns?
Each AMPH pattern is scored by its historical win rate — the share of the last 10 years it repeated in the same direction. AMPH currently shows 775 recurring windows (499 bullish, 276 bearish). Seasonality describes historical tendencies only; it is not a prediction, and past performance does not guarantee future results.
What is AMPH stock seasonality?
Stock seasonality is the tendency of a stock to perform in a similar way during the same period each year. By analysing Amphstar Pharmaceuticals, Inc.'s price history across many years, SeasonalityX identifies recurring calendar windows — exact start and end dates — where AMPH 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.