The takeaway
Ameresco Inc shows a pronounced seasonal pattern over 10 years of data — strongest in May (+16.6%) and softest in April (−7.6%).
Right now
In July, the stock has risen 70% of years, averaging +7.9%, about +5.7 pts better than the S&P 500.
The full picture
Ameresco Inc's most dependable month has been May, higher in 9 of 10 years; April 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 May (+15.9 pts); it has trailed the market most in April (−9.2 pts).
“vs S&P” is Ameresco Inc’s average for a month minus the S&P 500’s average for that same month — isolating Ameresco Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, May has closed higher 100% of the time versus 90% across the last 10 years — the pattern is strengthening.
Figures are the typical (median) May 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: May, up in 9 of 10 Mays while the other eleven tend to blur together.
The headline flatters a touch — its +16.6% average sits well above the +7.6% a typical year delivers, the work of a few big Mays. That reliability comes with real swings, mind — even May ranges by 22.3% 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: May has cleared the S&P 500 by +15.9 points above the index. That consistency sets it apart from the field, where the average stock manages May only about 55% of the time.
The strength clusters rather than stands alone — May–September forms a firm stretch that carries much of the year. At the other end of the calendar, April has been the soft spot — the weakest of 4 months that average a loss (−7.6%), and the edge isn't year-round — the stock has trailed the S&P 500 in April, December, and January. Its roughest month on record was a −43.5% February in 2025 — a reminder of how hard even a seasonal name can fall.
May has now closed higher 6 years running. If anything it has sharpened recently — the last five Mays run ahead of the earlier years.
The takeaway is less about when to buy than what to expect: May 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 (May), its worst (April), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (May, +16.6%) has run well ahead of its worst (April, −7.6%) — the heatmap above shows how steady that gap has been year to year.
May has been the strongest, averaging +16.6% and closing higher in 9 of 10 years since 2016.
It's the weakest, averaging −7.6% — 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