The takeaway
ADTRAN Inc shows a pronounced seasonal pattern over 10 years of data — strongest in July (+7.6%) and softest in March (−5.3%).
Right now
In July, the stock has risen 70% of years, averaging +7.6%, about +5.5 pts better than the S&P 500.
The full picture
ADTRAN Inc's most dependable month has been July, higher in 7 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 July (+5.5 pts); it has trailed the market most in October (−6.6 pts).
“vs S&P” is ADTRAN Inc’s average for a month minus the S&P 500’s average for that same month — isolating ADTRAN Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, July has closed higher 80% of the time versus 70% across the last 10 years — the pattern is strengthening.
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
Strip the year back and a single month does the heavy lifting: July, up in 7 of 10 Julys while the other eleven tend to blur together.
Its average (+7.6%) and median (+8.8%) 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 July ranges by 17.1% from year to year, so any single year can land far from the average. Crucially, the gain is the stock's own rather than a rising tide's: July has cleared the S&P 500 by +5.5 points above the index. Some of that is a strong month market-wide, mind — July rises for about 61% of stocks — so the tendency is real if not unique.
A few other months pull their weight: November and December have also closed higher more often than not. The weaker half of the year is plainer: March has been the soft spot — the weakest of 5 months that average a loss (−5.3%), and the edge isn't year-round — the stock has trailed the S&P 500 in October, March, and April. Its roughest month on record was a −41.2% April in 2023 — a reminder of how hard even a seasonal name can fall.
If anything it has sharpened recently — the last five Julys run ahead of the earlier years.
The takeaway is less about when to buy than what to expect: July 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 (July), its worst (March), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (July, +7.6%) has run well ahead of its worst (March, −5.3%) — the heatmap above shows how steady that gap has been year to year.
July has been the strongest, averaging +7.6% and closing higher in 7 of 10 years since 2016.
It's the weakest, averaging −5.3% — 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