The takeaway
Dimensional Global ex US Core Fixed Income ETF shows a slight seasonal lean over 3 years of data — strongest in September (+1.1%) and softest in December (+0.5%).
Right now
In July, the fund has risen 50% of years, averaging +1.2%, roughly 0.9 pts behind the S&P 500.
The full picture
Dimensional Global ex US Core Fixed Income ETF's most dependable month has been September, higher in 2 of 2 years; December has been its least reliable, up just 33% of the time.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Win rate % | ||||||||||||
| Median return % | ||||||||||||
| 2025 | ||||||||||||
| 2024 | ||||||||||||
| 2023 | — | — | — | — | — | — | — | — | — | — |
Month by month
The fund's clearest edge over the S&P 500 lands in September (+1.2 pts); it has trailed the market most in April (−1.8 pts).
“vs S&P” is Dimensional Global ex US Core Fixed Income ETF’s average for a month minus the S&P 500’s average for that same month — isolating Dimensional Global ex US Core Fixed Income 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 2 years versus the last 3(the heatmap’s default window). This verdict stays anchored to that 3-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. September stands out, higher in all 2 Septembers, but it heads a clutch of months that pull the year reliably upward.
Its average (+1.1%) and median (+1.1%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. Crucially, the gain is the fund's own rather than a rising tide's: September has cleared the S&P 500 by +1.2 points above the index. It bucks the broad tape, besides: September lifts just 39% of stocks across the market.
A few other months pull their weight: January, May, and June have also closed higher more often than not. The weaker half of the year is plainer: December 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 April, November, and October.
The takeaway is less about when to buy than what to expect: September aside, the fund's months offer little reliable tilt. With a short 3-year record, the signal is best held loosely.
Short answers on the fund's best month (September), its worst (December), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — September is the firmest (+1.1%) and December the softest (+0.5%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
September has been the strongest, averaging +1.1% and closing higher in all 2 years on record since 2023.
It's the weakest month, but it has still averaged a small gain (+0.5%) — quiet rather than genuinely bad.
Explore
These names have the strongest July track records on record — a starting point for comparison.
Before you trade