The takeaway
Otter Tail Corporation shows a moderate seasonal pattern over 10 years of data — strongest in October (+3.0%) and softest in September (−2.7%).
Right now
In July, the stock has risen 80% of years, averaging +2.3% — essentially in line with the S&P 500.
The full picture
Otter Tail Corporation's most dependable month has been October, higher in 8 of 10 years; September has been its least reliable, up just 50% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in May (+2.2 pts); it has trailed the market most in September (−2.5 pts).
“vs S&P” is Otter Tail Corporation’s average for a month minus the S&P 500’s average for that same month — isolating Otter Tail Corporation’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, October has closed higher 80% of the time versus 80% across the last 10 years — the pattern is holding.
Figures are the typical (median) October 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. October stands out, higher in 8 of 10 Octobers, but it heads a clutch of months that pull the year reliably upward.
Its average (+3.0%) and median (+4.2%) 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: October has cleared the S&P 500 by +2.0 points above the index. That consistency sets it apart from the field, where the average stock manages October only about 53% of the time.
The strength clusters rather than stands alone — October–January forms a firm stretch that carries much of the year. The weaker half of the year is plainer: September has been the soft spot — the only month to average an outright loss (−2.7%), and the edge isn't year-round — the stock has trailed the S&P 500 in September and April. Its roughest month on record was a −19.4% September in 2022 — a reminder of how hard even a seasonal name can fall.
A long streak recently broke — October had risen 6 years straight before a −4.2% reading in 2025. Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
The takeaway is less about when to buy than what to expect: October aside, the stock's months offer little reliable tilt.
Short answers on the stock's best month (October), its worst (September), and whether it really trades seasonally.
Yes, to a moderate degree. Since 2016 its best month (October, +3.0%) has run well ahead of its worst (September, −2.7%) — the heatmap above shows how steady that gap has been year to year.
October has been the strongest, averaging +3.0% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −2.7% — 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