The takeaway
iShares ESG USD Corporate Bond ETF shows a slight seasonal lean over 9 years of data — strongest in May (+1.1%) and softest in October (−0.8%).
Right now
In July, the fund has risen 78% of years, averaging +1.2%, roughly 1.0 pts behind the S&P 500.
The full picture
iShares ESG USD Corporate Bond ETF's most dependable month has been May, higher in 7 of 8 years; October has been its least reliable, up just 33% of the time.
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| 2017 | — | — | — | — | — | — |
Month by month
The fund's clearest edge over the S&P 500 lands in January (+0.9 pts); it has trailed the market most in April (−2.0 pts).
“vs S&P” is iShares ESG USD Corporate Bond ETF’s average for a month minus the S&P 500’s average for that same month — isolating iShares ESG USD Corporate Bond ETF’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, May has closed higher 80% of the time versus 88% across the last 9 years — the pattern is holding.
Figures are the typical (median) May return and how often it rose — the last 5 years versus the last 9(the heatmap’s default window). This verdict stays anchored to that 9-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 May is the anchor — it has closed higher in 7 of 8 Mays, the steadiest beat on its year.
The strength looks broad-based rather than freakish: its average (+1.1%) and median (+0.9%) sit close together, so no single blow-out year is flattering the figure. No month is steadier: May's returns vary by just 0.8% year to year, and even its worst May in 9 years lost only 0.2% — the gentlest downside anywhere on its calendar. Set against the S&P 500, mind, May is close to a wash — the gain mirrors the market more than it beats it. Few peers keep such company in May — the typical stock clears it just 55% of the time.
May anchors a run, too: the May-through-July window has been the fund's reliable season. At the other end of the calendar, October has been the soft spot — the weakest of 3 months that average a loss (−0.8%), and the edge isn't year-round — the fund has trailed the S&P 500 in April, October, and March.
Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
For a fund this dependable in May, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on. With a short 9-year record, the signal is best held loosely.
Short answers on the fund's best month (May), its worst (October), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — May is the firmest (+1.1%) and October the softest (−0.8%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
May has been the strongest, averaging +1.1% and closing higher in 7 of 8 years since 2017.
It's the weakest, averaging −0.8% — 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