The takeaway
SPDR® S&P Biotech ETF shows a pronounced seasonal pattern over 10 years of data — strongest in November (+5.4%) and softest in March (−4.9%).
Right now
In July, the fund has risen 60% of years, averaging +1.1%, roughly 1.0 pts behind the S&P 500.
The full picture
SPDR® S&P Biotech ETF's most dependable month has been November, higher in 8 of 10 years; March has been its least reliable, up just 20% of the time.
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Month by month
The fund's clearest edge over the S&P 500 lands in June (+3.6 pts); it has trailed the market most in March (−6.0 pts).
“vs S&P” is SPDR® S&P Biotech ETF’s average for a month minus the S&P 500’s average for that same month — isolating SPDR® S&P Biotech ETF’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, November has closed higher 80% of the time versus 80% 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 8 of 10 Novembers while the other eleven tend to blur together.
Its average (+5.4%) and median (+5.6%) 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 November ranges by 8.3% from year to year, so any single year can land far from the average. Crucially, the gain is the fund's own rather than a rising tide's: November has cleared the S&P 500 by +3.0 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: January, April, and June have also closed higher more often than not. At the other end of the calendar, March has been the soft spot — the weakest of 4 months that average a loss (−4.9%), and the edge isn't year-round — the fund has trailed the S&P 500 in March, October, and July. Its roughest month on record was a −25.5% January in 2016 — 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 fund's months offer little reliable tilt.
Short answers on the fund's best month (November), its worst (March), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (November, +5.4%) has run well ahead of its worst (March, −4.9%) — the heatmap above shows how steady that gap has been year to year.
November has been the strongest, averaging +5.4% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −4.9% — 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