The takeaway
Alkermes Plc shows a moderate seasonal pattern over 10 years of data — strongest in May (+2.1%) and softest in March (−3.1%).
Right now
In July, the stock has fallen 50% of years, averaging −1.3%, roughly 3.5 pts behind the S&P 500.
The full picture
Alkermes Plc's most dependable month has been May, higher in 7 of 10 years; March has been its least reliable, up just 40% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in February (+2.4 pts); it has trailed the market most in March (−4.2 pts).
“vs S&P” is Alkermes Plc’s average for a month minus the S&P 500’s average for that same month — isolating Alkermes Plc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, May has closed higher 80% of the time versus 70% across the last 10 years — the pattern is strengthening.
Figures are the typical (median) May return and how often it rose — the last 5 years versus the last 10(the heatmap’s default window). This verdict stays anchored to that 10-year window even if you zoom the chart, so it never disagrees with the badges above.
In plain English
Strip the year back and a single month does the heavy lifting: May, up in 7 of 10 Mays while the other eleven tend to blur together.
Its average (+2.1%) and median (+1.7%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. That reliability comes with real swings, mind — even May ranges by 11.7% from year to year, so any single year can land far from the average. Crucially, the gain is the stock's own rather than a rising tide's: May has cleared the S&P 500 by +1.4 points above the index. That consistency sets it apart from the field, where the average stock manages May only about 55% of the time.
A few other months pull their weight: January, November, and December have also closed higher more often than not. On the other side of the ledger, March has been the soft spot — the weakest of 7 months that average a loss (−3.1%), and the edge isn't year-round — the stock has trailed the S&P 500 in March, October, and July. Its roughest month on record was a −57.2% January in 2016 — a reminder of how hard even a seasonal name can fall.
If anything it has sharpened recently — the last five Mays run ahead of the earlier years.
The takeaway is less about when to buy than what to expect: May aside, the stock's months offer little reliable tilt.
Short answers on the stock's best month (May), its worst (March), and whether it really trades seasonally.
Yes, to a moderate degree. Since 2016 its best month (May, +2.1%) has run well ahead of its worst (March, −3.1%) — the heatmap above shows how steady that gap has been year to year.
May has been the strongest, averaging +2.1% and closing higher in 7 of 10 years since 2016.
It's the weakest, averaging −3.1% — historically a soft spot, though it still varies from year to year.
Explore
These names have the strongest July track records on record — a starting point for comparison.
Before you trade