The takeaway
iShares Russell Mid-Cap ETF shows a moderate seasonal pattern over 10 years of data — strongest in July (+3.3%) and softest in September (−1.2%).
Right now
In July, the fund has risen 100% of years, averaging +3.3%, about +1.1 pts better than the S&P 500.
The full picture
iShares Russell Mid-Cap ETF's most dependable month has been July, higher in 10 of 10 years; September has been its least reliable, up just 50% of the time.
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Month by month
The fund's clearest edge over the S&P 500 lands in November (+2.3 pts); it has trailed the market most in March (−2.3 pts).
“vs S&P” is iShares Russell Mid-Cap ETF’s average for a month minus the S&P 500’s average for that same month — isolating iShares Russell Mid-Cap 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
This is a fund you can almost set a calendar by, and July is the anchor — it has closed higher in all 10 Julys, the steadiest beat on its year.
The strength looks broad-based rather than freakish: its average (+3.3%) and median (+3.0%) sit close together, so no single blow-out year is flattering the figure. No month is steadier: July's returns vary by just 2.6% year to year, and even its worst July in 10 years lost only 0.2% — the gentlest downside anywhere on its calendar. Better still, that strength is the fund's own and not just a buoyant market — July has outpaced the S&P 500 by +1.1 points on average. Few peers keep such company in July — the typical stock clears it just 61% of the time.
July anchors a run, too: the March-through-August window has been the fund's reliable season. The weaker half of the year is plainer: September has been the soft spot — the weakest of 3 months that average a loss (−1.2%), and the edge isn't year-round — the fund has trailed the S&P 500 in March, October, and December. Its roughest month on record was a −22.3% March in 2020 — a reminder of how hard even a seasonal name can fall.
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.
For a fund this dependable in July, 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 (July), its worst (September), and whether it really trades seasonally.
Yes, to a moderate degree. Since 2016 its best month (July, +3.3%) has run well ahead of its worst (September, −1.2%) — the heatmap above shows how steady that gap has been year to year.
July has been the strongest, averaging +3.3% and closing higher in all 10 years on record since 2016.
It's the weakest, averaging −1.2% — 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