The takeaway
ProShares Short High Yield shows a slight seasonal lean over 10 years of data — strongest in October (+0.4%) and softest in August (−0.3%).
Right now
In July, the fund has fallen 20% of years, averaging −1.7%, roughly 3.8 pts behind the S&P 500.
The full picture
ProShares Short High Yield's most dependable month has been October, higher in 6 of 10 years; August has been its least reliable, up just 10% of the time.
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Month by month
Across the year the fund has stayed close to the S&P 500 — no single month stands out as a real edge.
“vs S&P” is ProShares Short High Yield’s average for a month minus the S&P 500’s average for that same month — isolating ProShares Short High Yield’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, October has closed higher 80% of the time versus 60% across the last 10 years — the pattern is strengthening.
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
The year leans October's way without overwhelming the rest of it: the fund has closed higher in 6 of 10 Octobers, its most dependable month if not a dominant one.
Its average (+0.4%) and median (+0.4%) 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 1.1% spread).
Only February comes anywhere near it for reliability. The weaker half of the year is plainer: August is the year's quietest corner, essentially flat on average, and the edge isn't year-round — the fund has trailed the S&P 500 in July, November, and April.
If anything it has sharpened recently — the last five Octobers run ahead of the earlier years.
Treat it as a tendency rather than a rule — seasonality describes the past, not a promise.
Short answers on the fund's best month (October), its worst (August), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — October is the firmest (+0.4%) and August the softest (−0.3%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
October has been the strongest, averaging +0.4% and closing higher in 6 of 10 years since 2016.
It's the weakest, averaging −0.3% — 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