SPY vs VO Overlap

SPY is a U.S. large-cap core ETF from SPDR, while VO is a mid-cap U.S. equity ETF from Vanguard. SPY and VO show limited overlap, with an estimated weighted overlap of 15.93%. They share 250 holdings in the loaded dataset, led by NEM, GLW, and HWM.

15.9% overlap
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250Shared Holdings
OK
Low Overlap

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Quick Answer

SPY is a U.S. large-cap core ETF from SPDR, while VO is a mid-cap U.S. equity ETF from Vanguard. SPY and VO show limited overlap, with an estimated weighted overlap of 15.93%. They share 250 holdings in the loaded dataset, led by NEM, GLW, and HWM.

  • 15.93% weighted overlap across 250 shared holdings.
  • The top three shared holdings explain 3.65% of the measured overlap.
  • SPY is the broader fund, while VO is more targeted.
  • The overlap is mostly explained by the top shared positions rather than sector labels alone.
  • Holding both can still add materially different exposure.

Data Freshness

SPY holdings
Mar 12, 2026
VO holdings
Mar 12, 2026
Overlap computed
Mar 13, 2026
Data source
Financial Modeling Prep

Review the methodology for the overlap formula and refresh policy.

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About These ETFs

ETF A

SPY

State Street SPDR S&P 500 ETF Trust

Issuer
SPDR
Asset class
Equity
Expense ratio
0.0945%
AUM
$678B
Inception
Jan 22, 1993

ETF B

VO

Vanguard Mid-Cap ETF

Issuer
Vanguard
Asset class
Mid Cap Equity
Expense ratio
0.03%
AUM
$203B
Inception
Jan 26, 2004

What Stands Out In This Comparison

01

What This Means

SPY is a U.S. large-cap core ETF from SPDR, while VO is a mid-cap U.S. equity ETF from Vanguard. SPY and VO do not own much of the same portfolio weight. That usually means you are combining different parts of the market, with only a small amount of duplication through names like NEM, GLW, and HWM.

02

How They Differ

SPY is a U.S. large-cap core ETF from SPDR, while VO is a mid-cap U.S. equity ETF from Vanguard. SPY is the broader fund, while VO is the more targeted sleeve. VO has the lower expense ratio, while SPY charges more for its exposure.

03

What Drives The Overlap

The overlap is driven by a relatively small set of large shared positions. The top three shared holdings account for 3.65% of the score, which means the result is heavily influenced by the biggest common weights rather than a long tail of tiny positions.

04

When One May Fit Better

If you want the broader portfolio building block, SPY is usually the wider choice. If you want the more focused tilt, VO is the narrower expression. VO has the lower expense ratio, while SPY charges more for its exposure.

Overlap Driver Snapshot

Concentration

The top three shared holdings explain 3.65% of the full overlap score.

That helps show whether the score comes from a handful of giant shared positions or from a broader mix of common holdings.

Shared Sector Tilt

Sector tags are not consistently available for the biggest shared positions in this dataset, so this comparison leans more on the specific holdings than on sector labels.

Top Shared Holdings

These are the holdings contributing the most to the overlap score between SPY and VO.

HoldingSPY Wt.VO Wt.Overlap
NEM0.22%1.31%0.22%
GLW0.18%0.85%0.18%
HWM0.18%0.89%0.18%
CEG0.17%0.94%0.17%
WDC0.16%0.91%0.16%
WMB0.16%0.44%0.16%
PWR0.14%0.76%0.14%
STX0.14%0.93%0.14%
JCI0.14%0.39%0.14%
FDX0.14%0.36%0.14%

Why These ETFs Overlap

SPY is a U.S. large-cap core ETF from SPDR, while VO is a mid-cap U.S. equity ETF from Vanguard. The overlap exists because both funds allocate meaningful weight to the same holdings. In this dataset, the biggest shared drivers are NEM, GLW, and HWM, which appear in both portfolios and push the overlap score higher.

Holding both SPY and VO can make sense if you want exposure to different sleeves of the market. The overlap is small enough that both funds may still improve diversification.

Related Comparisons

Frequently Asked Questions About SPY and VO

What is the overlap between SPY and VO?+
SPY and VO currently show an estimated weighted overlap of 15.93% based on the loaded holdings data.
How many holdings do SPY and VO share?+
They share 250 holdings in the current dataset.
Is the SPY and VO overlap high?+
The current verdict is Low Overlap. That means the two ETFs have limited duplication in portfolio weight.
Why do SPY and VO overlap?+
SPY and VO overlap because the same large positions appear in both funds. In this comparison, the top three shared holdings explain 3.65% of the measured overlap score.
Which ETF is broader, SPY or VO?+
SPY is the broader fund, while VO is the more targeted sleeve. That does not automatically make one better, but it helps explain why the pair can overlap while still serving different roles.

How Overlap Is Calculated

A straightforward approach used by portfolio analysts.

Overlap = sum(min(Weight_A, Weight_B)) for each shared holding

For every stock that appears in both ETFs, we take the smaller of the two weights. Adding up all those minimums gives the total overlap percentage. A score of 100% means the two ETFs hold the exact same stocks in the same proportions.

Want the full explanation? Read the methodology page.

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