The takeaway
iShares 1-5 Year Investment Grade Corporate Bond ETF shows a slight seasonal lean over 10 years of data — strongest in July (+0.5%) and softest in September (−0.2%).
Right now
In July, the fund has risen 100% of years, averaging +0.5%, roughly 1.6 pts behind the S&P 500.
The full picture
iShares 1-5 Year Investment Grade Corporate Bond ETF's most dependable month has been July, higher in 10 of 10 years; September has been its least reliable, up just 20% of the time.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Win rate % | ||||||||||||
| Median return % | ||||||||||||
| 2025 | ||||||||||||
| 2024 | ||||||||||||
| 2023 | ||||||||||||
| 2022 | ||||||||||||
| 2021 | ||||||||||||
| 2020 | ||||||||||||
| 2019 | ||||||||||||
| 2018 | ||||||||||||
| 2017 | ||||||||||||
| 2016 |
Month by month
The fund's clearest edge over the S&P 500 lands in January (+0.6 pts); it has trailed the market most in November (−1.8 pts).
“vs S&P” is iShares 1-5 Year Investment Grade Corporate Bond ETF’s average for a month minus the S&P 500’s average for that same month — isolating iShares 1-5 Year Investment Grade Corporate Bond ETF’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, July has closed higher 100% of the time versus 100% across the last 10 years — the pattern is holding.
Figures are the typical (median) July 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. July stands out, higher in all 10 Julys, but it heads a clutch of months that pull the year reliably upward.
Its average (+0.5%) 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 among its calmest months, too, its returns swinging least from year to year (a 0.5% spread), and even its worst July in 10 years lost only 0.1% — the gentlest downside anywhere on its calendar. That consistency sets it apart from the field, where the average stock manages July only about 61% of the time.
The strength clusters rather than stands alone — March–August forms a firm stretch that carries much of the year. At the other end of the calendar, September 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 November, July, and April.
July has now closed higher 10 years running. Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.
The takeaway is less about when to buy than what to expect: July aside, the fund's months offer little reliable tilt.
Short answers on the fund's best month (July), its worst (September), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — July is the firmest (+0.5%) and September the softest (−0.2%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
July has been the strongest, averaging +0.5% and closing higher in all 10 years on record since 2016.
It's the weakest, averaging −0.2% — 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