The takeaway
IDEXX Laboratories Inc shows a pronounced seasonal pattern over 10 years of data — strongest in July (+6.5%) and softest in September (−2.9%).
Right now
In July, the stock has risen 80% of years, averaging +6.5%, about +4.3 pts better than the S&P 500.
The full picture
IDEXX Laboratories Inc's most dependable month has been July, higher in 8 of 10 years; September has been its least reliable, up just 20% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in July (+4.3 pts); it has trailed the market most in September (−2.7 pts).
“vs S&P” is IDEXX Laboratories Inc’s average for a month minus the S&P 500’s average for that same month — isolating IDEXX Laboratories Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, July has closed higher 60% of the time versus 80% across the last 10 years — the pattern is weakening.
Figures are the typical (median) July 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
Dependability is the through-line here. July stands out, higher in 8 of 10 Julys, but it heads a clutch of months that pull the year reliably upward.
Its average (+6.5%) and median (+5.3%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. Crucially, the gain is the stock's own rather than a rising tide's: July has cleared the S&P 500 by +4.3 points above the index. That consistency sets it apart from the field, where the average stock manages July only about 61% of the time.
The lift is near-universal — strength runs through almost every month of the year, not one window. On the other side of the ledger, September has been the soft spot — the weakest of 2 months that average a loss (−2.9%), and the edge isn't year-round — the stock has trailed the S&P 500 in September, October, and March. Its roughest month on record was a −22.2% April in 2022 — a reminder of how hard even a seasonal name can fall.
At its steadiest, July strung together 8 straight positive years. The pattern has softened of late, July's last five years slipping below its longer-run record.
The takeaway is less about when to buy than what to expect: July aside, the stock's months offer little reliable tilt.
Short answers on the stock's best month (July), its worst (September), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (July, +6.5%) has run well ahead of its worst (September, −2.9%) — the heatmap above shows how steady that gap has been year to year.
July has been the strongest, averaging +6.5% 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