The takeaway
Vanguard Tax-Exempt Bond Index Fund ETF Shares shows a slight seasonal lean over 10 years of data — strongest in November (+1.2%) and softest in September (−0.5%).
Right now
In July, the fund has risen 80% of years, averaging +0.7%, roughly 1.5 pts behind the S&P 500.
The full picture
Vanguard Tax-Exempt Bond Index Fund ETF Shares's most dependable month has been November, higher in 8 of 10 years; September has been its least reliable, up just 20% of the time.
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Month by month
Across the year the fund has stayed close to the S&P 500 — no single month stands out as a real edge.
“vs S&P” is Vanguard Tax-Exempt Bond Index Fund ETF Shares’s average for a month minus the S&P 500’s average for that same month — isolating Vanguard Tax-Exempt Bond Index Fund ETF Shares’s own seasonal edge from broad market drift.
Reality check
Over the last 5 years, November has closed higher 100% of the time versus 80% 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
Dependability is the through-line here. November stands out, higher in 8 of 10 Novembers, but it heads a clutch of months that pull the year reliably upward.
Its average (+1.2%) and median (+1.0%) land within a hair of each other — the tell of steady, year-after-year gains rather than one outlier doing the work. That consistency sets it apart from the field, where the average stock manages November only about 62% of the time.
The strength clusters rather than stands alone — November–January forms a firm stretch that carries much of the year. The weaker half of the year is plainer: 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 April, July, and October.
November has now closed higher 8 years running. If anything it has sharpened recently — the last five Novembers run ahead of the earlier years.
The takeaway is less about when to buy than what to expect: November aside, the fund's months offer little reliable tilt.
Short answers on the fund's best month (November), its worst (September), and whether it really trades seasonally.
Only mildly. The fund's months are fairly even — November is the firmest (+1.2%) and September the softest (−0.5%), a narrow spread that points to weak seasonality rather than a strong calendar effect.
November has been the strongest, averaging +1.2% and closing higher in 8 of 10 years since 2016.
It's the weakest, averaging −0.5% — 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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