The takeaway
JPMorgan Mortgage-Backed Securities ETF shows a slight seasonal lean over 1 years of data — strongest in September (+1.2%) and softest in July (−0.7%).
Right now
In July, the fund has fallen 0% of years, averaging −0.7%, roughly 2.9 pts behind the S&P 500.
The full picture
JPMorgan Mortgage-Backed Securities ETF's most dependable month has been September, higher in 1 of 1 years; July has been its least reliable, up just 0% of the time.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Win rate % | — | — | — | — | — | — | ||||||
| Median return % | — | — | — | — | — | — | ||||||
| 2025 | — | — | — | — | — | — |
Month by month
The fund's clearest edge over the S&P 500 lands in September (+1.3 pts); it has trailed the market most in July (−2.9 pts).
“vs S&P” is JPMorgan Mortgage-Backed Securities ETF’s average for a month minus the S&P 500’s average for that same month — isolating JPMorgan Mortgage-Backed Securities ETF’s own seasonal edge from broad market drift.
Reality check
Not enough recent September history to say whether the pattern still holds.
Figures are the typical (median) September return and how often it rose — the last 1 years versus the last 1(the heatmap’s default window). This verdict stays anchored to that 1-year window even if you zoom the chart, so it never disagrees with the badges above.
In plain English
This is a fund you can almost set a calendar by, and September is the anchor — it has closed higher in all 1 Septembers, the steadiest beat on its year.
The strength looks broad-based rather than freakish: its average (+1.2%) and median (+1.2%) sit close together, so no single blow-out year is flattering the figure. No month is steadier: September's returns vary by just 0.0% year to year, and even its worst September in 1 years lost only 1.2% — the gentlest downside anywhere on its calendar. Better still, that strength is the fund's own and not just a buoyant market — September has outpaced the S&P 500 by +1.3 points on average. It is the more striking for the company it keeps — September is a losing month for most of the market, where barely 39% of names gain ground.
September anchors a run, too: the August-through-December window has been the fund's reliable season. At the other end of the calendar, July has been the soft spot — the only month to average an outright loss (−0.7%), and the edge isn't year-round — the fund has trailed the S&P 500 in July, November, and December.
For a fund this dependable in September, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on. With a short 1-year record, the signal is best held loosely.
Short answers on the fund's best month (September), its worst (July), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — September is the firmest (+1.2%) and July the softest (−0.7%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
September has been the strongest, averaging +1.2% and closing higher in its one year on record since 2025.
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