The takeaway
CommVault Systems Inc shows a pronounced seasonal pattern over 10 years of data — strongest in May (+4.3%) and softest in October (−5.6%).
Right now
In July, the stock has risen 60% of years, averaging +5.6%, about +3.4 pts better than the S&P 500.
The full picture
CommVault Systems Inc's most dependable month has been May, higher in 8 of 10 years; October 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 January (+4.3 pts); it has trailed the market most in October (−6.6 pts).
“vs S&P” is CommVault Systems Inc’s average for a month minus the S&P 500’s average for that same month — isolating CommVault Systems 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 80% 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
Dependability is the through-line here. May stands out, higher in 8 of 10 Mays, but it heads a clutch of months that pull the year reliably upward.
Its average (+4.3%) and median (+3.3%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. That reliability comes with real swings, mind — even May ranges by 8.3% 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 +3.6 points above the index. That consistency sets it apart from the field, where the average stock manages May only about 55% of the time.
A few other months pull their weight: April, July, and September have also closed higher more often than not. The weaker half of the year is plainer: October has been the soft spot — the weakest of 2 months that average a loss (−5.6%), and the edge isn't year-round — the stock has trailed the S&P 500 in October, February, and April. Its roughest month on record was a −25.1% October in 2025 — a reminder of how hard even a seasonal name can fall.
May has now closed higher 5 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.
Short answers on the stock's best month (May), its worst (October), and whether it really trades seasonally.
Yes, to a pronounced degree. Since 2016 its best month (May, +4.3%) has run well ahead of its worst (October, −5.6%) — the heatmap above shows how steady that gap has been year to year.
May has been the strongest, averaging +4.3% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −5.6% — 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