The takeaway
Insmed Inc shows a pronounced seasonal pattern over 10 years of data — strongest in November (+9.1%) and softest in March (−6.6%).
Right now
In July, the stock has fallen 60% of years, averaging −0.2%, roughly 2.4 pts behind the S&P 500.
The full picture
Insmed Inc's most dependable month has been November, higher in 9 of 10 years; March has been its least reliable, up just 20% of the time.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Win rate % | ||||||||||||
| Median return % | ||||||||||||
| 2025 | ||||||||||||
| 2024 | ||||||||||||
| 2023 | ||||||||||||
| 2022 | ||||||||||||
| 2021 | ||||||||||||
| 2020 | ||||||||||||
| 2019 | ||||||||||||
| 2018 | ||||||||||||
| 2017 | ||||||||||||
| 2016 |
Month by month
The stock's clearest edge over the S&P 500 lands in September (+17.8 pts); it has trailed the market most in March (−7.6 pts).
“vs S&P” is Insmed Inc’s average for a month minus the S&P 500’s average for that same month — isolating Insmed Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, November has closed higher 80% of the time versus 90% across the last 10 years — the pattern is weakening.
Figures are the typical (median) November 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: November, up in 9 of 10 Novembers while the other eleven tend to blur together.
Its average (+9.1%) and median (+10.8%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. It is also the calendar's calmest month, its returns swinging least from year to year (a 9.3% spread). Crucially, the gain is the stock's own rather than a rising tide's: November has cleared the S&P 500 by +6.7 points above the index. That consistency sets it apart from the field, where the average stock manages November only about 62% of the time.
A few other months pull their weight: June, July, and August have also closed higher more often than not. On the other side of the ledger, March has been the soft spot — the weakest of 4 months that average a loss (−6.6%), and the edge isn't year-round — the stock has trailed the S&P 500 in March, December, and October. Its roughest month on record was a −38.6% March in 2020 — a reminder of how hard even a seasonal name can fall.
The pattern has softened of late, November's last five years slipping below its longer-run record.
The takeaway is less about when to buy than what to expect: November aside, the stock's months offer little reliable tilt. With returns that swing hard year to year, the signal is best held loosely.
Short answers on the stock's best month (November), its worst (March), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (November, +9.1%) has run well ahead of its worst (March, −6.6%) — the heatmap above shows how steady that gap has been year to year.
November has been the strongest, averaging +9.1% and closing higher in 9 of 10 years since 2016.
It's the weakest, averaging −6.6% — 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