The takeaway
Comcast Corp shows a moderate seasonal pattern over 10 years of data — strongest in July (+3.1%) and softest in September (−3.7%).
Right now
In July, the stock has risen 80% of years, averaging +3.1%, about +1.0 pts better than the S&P 500.
The full picture
Comcast Corp's most dependable month has been July, higher in 8 of 10 years; September has been its least reliable, up just 40% of the time.
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Month by month
The stock's clearest edge over the S&P 500 lands in November (+2.7 pts); it has trailed the market most in October (−3.8 pts).
“vs S&P” is Comcast Corp’s average for a month minus the S&P 500’s average for that same month — isolating Comcast Corp’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
Strip the year back and a single month does the heavy lifting: July, up in 8 of 10 Julys while the other eleven tend to blur together.
Its average (+3.1%) 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: July has cleared the S&P 500 by +1.0 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 strength clusters rather than stands alone — May–August 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 weakest of 4 months that average a loss (−3.7%), and the edge isn't year-round — the stock has trailed the S&P 500 in October, September, and March. Its roughest month on record was a −20.5% September in 2022 — a reminder of how hard even a seasonal name can fall.
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 moderate degree. Since 2016 its best month (July, +3.1%) has run well ahead of its worst (September, −3.7%) — the heatmap above shows how steady that gap has been year to year.
July has been the strongest, averaging +3.1% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −3.7% — 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