The takeaway
iShares 10-20 Year Treasury Bond ETF shows a moderate seasonal pattern over 10 years of data — strongest in November (+1.5%) and softest in October (−1.9%).
Right now
In July, the fund has risen 60% of years, averaging +1.2%, roughly 1.0 pts behind the S&P 500.
The full picture
iShares 10-20 Year Treasury Bond ETF's most dependable month has been November, higher in 7 of 10 years; October has been its least reliable, up just 20% of the time.
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Month by month
The fund's clearest edge over the S&P 500 lands in January (+0.8 pts); it has trailed the market most in April (−3.1 pts).
“vs S&P” is iShares 10-20 Year Treasury Bond ETF’s average for a month minus the S&P 500’s average for that same month — isolating iShares 10-20 Year Treasury Bond ETF’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, November has closed higher 100% of the time versus 70% across the last 10 years — the pattern is strengthening.
Figures are the typical (median) November 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
This is a fund you can almost set a calendar by, and November is the anchor — it has closed higher in 7 of 10 Novembers, the steadiest beat on its year.
The strength looks broad-based rather than freakish: its average (+1.5%) and median (+1.2%) sit close together, so no single blow-out year is flattering the figure. Some of that is a strong month market-wide, mind — November rises for about 62% of stocks — so the tendency is real if not unique.
It doesn't stand entirely alone — January, March, and June have leaned firm as well, if less emphatically. At the other end of the calendar, October has been the soft spot — the weakest of 3 months that average a loss (−1.9%), and the edge isn't year-round — the fund has trailed the S&P 500 in April, October, and September.
November has now closed higher 6 years running. If anything it has sharpened recently — the last five Novembers run ahead of the earlier years.
For a fund this dependable in November, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on.
Short answers on the fund's best month (November), its worst (October), and whether it really trades seasonally.
Yes, to a moderate degree. Since 2016 its best month (November, +1.5%) has run well ahead of its worst (October, −1.9%) — the heatmap above shows how steady that gap has been year to year.
November has been the strongest, averaging +1.5% and closing higher in 7 of 10 years since 2016.
It's the weakest, averaging −1.9% — 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.
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