The takeaway
Vertex Pharmaceuticals Inc shows a pronounced seasonal pattern over 10 years of data — strongest in January (+5.9%) and softest in September (−2.9%).
Right now
In July, the stock has risen 60% of years, averaging +2.4% — essentially in line with the S&P 500.
The full picture
Vertex Pharmaceuticals Inc's most dependable month has been January, higher in 8 of 10 years; September has been its least reliable, up just 10% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in January (+6.1 pts); it has trailed the market most in February (−3.2 pts).
“vs S&P” is Vertex Pharmaceuticals Inc’s average for a month minus the S&P 500’s average for that same month — isolating Vertex Pharmaceuticals Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, January has closed higher 80% of the time versus 80% across the last 10 years — the pattern is holding.
Figures are the typical (median) January 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 seasonal story is really one month's story — January. It has closed higher in 8 of 10 Januaries, a concentration the rest of the calendar can't touch.
The strength looks broad-based rather than freakish: its average (+5.9%) and median (+9.2%) sit close together, so no single blow-out year is flattering the figure. That reliability comes with real swings, mind — even January ranges by 11.8% from year to year, so any single year can land far from the average. Better still, that strength is the stock's own and not just a buoyant market — January has outpaced the S&P 500 by +6.1 points on average. Few peers keep such company in January — the typical stock clears it just 53% of the time.
It doesn't stand entirely alone — March, April, and May have leaned firm as well, if less emphatically. The weaker half of the year is plainer: September has been the soft spot — the weakest of 4 months that average a loss (−2.9%), and the edge isn't year-round — the stock has trailed the S&P 500 in February, September, and October.
Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
For a stock this dependable in January, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on.
Short answers on the stock's best month (January), its worst (September), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (January, +5.9%) has run well ahead of its worst (September, −2.9%) — the heatmap above shows how steady that gap has been year to year.
January has been the strongest, averaging +5.9% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −2.9% — 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