The takeaway
Kirby Corporation shows a pronounced seasonal pattern over 10 years of data — strongest in April (+6.7%) and softest in July (−4.5%).
Right now
In July, the stock has fallen 30% of years, averaging −4.5%, roughly 6.7 pts behind the S&P 500.
The full picture
Kirby Corporation's most dependable month has been April, higher in 8 of 10 years; July has been its least reliable, up just 30% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in April (+5.0 pts); it has trailed the market most in July (−6.7 pts).
“vs S&P” is Kirby Corporation’s average for a month minus the S&P 500’s average for that same month — isolating Kirby Corporation’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, April has closed higher 60% of the time versus 80% across the last 10 years — the pattern is weakening.
Figures are the typical (median) April 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
The seasonal story is really one month's story — April. It has closed higher in 8 of 10 Aprils, a concentration the rest of the calendar can't touch.
The strength looks broad-based rather than freakish: its average (+6.7%) and median (+5.7%) sit close together, so no single blow-out year is flattering the figure. That reliability comes with real swings, mind — even April ranges by 10.9% from year to year, so any single year can land far from the average. Better still, that strength is the stock's own and not just a buoyant market — April has outpaced the S&P 500 by +5.0 points on average. Few peers keep such company in April — the typical stock clears it just 55% of the time.
April anchors a run, too: the February-through-May window has been the stock's reliable season. At the other end of the calendar, July has been the soft spot — the weakest of 5 months that average a loss (−4.5%), and the edge isn't year-round — the stock has trailed the S&P 500 in July, June, and March. Its roughest month on record was a −33.0% March in 2020 — a reminder of how hard even a seasonal name can fall.
The pattern has softened of late, April's last five years slipping below its longer-run record.
For a stock this dependable in April, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on.
Short answers on the stock's best month (April), its worst (July), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (April, +6.7%) has run well ahead of its worst (July, −4.5%) — the heatmap above shows how steady that gap has been year to year.
April has been the strongest, averaging +6.7% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −4.5% — 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