The takeaway
T-Mobile US Inc shows a slight seasonal lean over 10 years of data — strongest in July (+2.2%) and softest in March (−0.7%).
Right now
In July, the stock has risen 70% of years, averaging +2.2% — essentially in line with the S&P 500.
The full picture
T-Mobile US Inc's most dependable month has been July, higher in 7 of 10 years; March 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 August (+2.4 pts); it has trailed the market most in March (−1.8 pts).
“vs S&P” is T-Mobile US Inc’s average for a month minus the S&P 500’s average for that same month — isolating T-Mobile US Inc’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, July has closed higher 40% of the time versus 70% 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
Dependability is the through-line here. July stands out, higher in 7 of 10 Julys, but it heads a clutch of months that pull the year reliably upward.
Its average (+2.2%) and median (+1.5%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. It is also the calendar's calmest month, its returns swinging least from year to year (a 3.2% spread), and even its worst July in 10 years lost only 1.3% — the gentlest downside anywhere on its calendar. Set against the S&P 500, mind, July is close to a wash — the gain mirrors the market more than it beats it. 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: January, April, and August have also closed higher more often than not. At the other end of the calendar, March has been the soft spot — the weakest of 2 months that average a loss (−0.7%), and the edge isn't year-round — the stock has trailed the S&P 500 in March, April, and September. Its roughest month on record was a −10.7% June in 2017 — 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 (March), and whether it really trades seasonally.
Only mildly. The stock's months are fairly even — July is the firmest (+2.2%) and March the softest (−0.7%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
July has been the strongest, averaging +2.2% and closing higher in 7 of 10 years since 2016.
It's the weakest, averaging −0.7% — 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