The takeaway
Assembly Biosciences Inc shows a pronounced seasonal pattern over 10 years of data — strongest in May (+4.2%) and softest in March (−5.5%).
Right now
In July, the stock has fallen 50% of years, averaging −1.1%, roughly 3.3 pts behind the S&P 500.
The full picture
Assembly Biosciences Inc's most dependable month has been May, higher in 6 of 10 years; March has been its least reliable, up just 30% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in October (+12.4 pts); it has trailed the market most in March (−6.5 pts).
“vs S&P” is Assembly Biosciences Inc’s average for a month minus the S&P 500’s average for that same month — isolating Assembly Biosciences Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, May has closed higher 60% of the time versus 60% 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
The year leans May's way without overwhelming the rest of it: the stock has closed higher in 6 of 10 Mays, its most dependable month if not a dominant one.
Its average (+4.2%) and median (+4.2%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. It is among its calmest months, too, its returns swinging least from year to year (a 10.2% spread), and even its worst May in 10 years lost only 8.5% — the gentlest downside anywhere on its calendar. Crucially, the gain is the stock's own rather than a rising tide's: May has cleared the S&P 500 by +3.5 points above the index.
The weaker half of the year is plainer: March has been the soft spot — the weakest of 5 months that average a loss (−5.5%), and the edge isn't year-round — the stock has trailed the S&P 500 in March, November, and July. Its roughest month on record was a −60.9% November in 2020 — 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.
Treat it as a tendency rather than a rule — seasonality describes the past, not a promise. With returns that swing hard year to year, the signal is best held loosely.
Short answers on the stock's best month (May), its worst (March), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (May, +4.2%) has run well ahead of its worst (March, −5.5%) — the heatmap above shows how steady that gap has been year to year.
May has been the strongest, averaging +4.2% and closing higher in 6 of 10 years since 2016.
It's the weakest, averaging −5.5% — 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