ITOT vs VO Overlap

ITOT is an equity ETF from IShares, while VO is a mid-cap U.S. equity ETF from Vanguard. ITOT and VO show limited overlap, with an estimated weighted overlap of 14.71%. They share 272 holdings in the loaded dataset, led by NEM, GLW, and VRT.

14.7% overlap
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272Shared Holdings
OK
Low Overlap

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Quick Answer

ITOT is an equity ETF from IShares, while VO is a mid-cap U.S. equity ETF from Vanguard. ITOT and VO show limited overlap, with an estimated weighted overlap of 14.71%. They share 272 holdings in the loaded dataset, led by NEM, GLW, and VRT.

  • 14.71% weighted overlap across 272 shared holdings.
  • The top three shared holdings explain 3.51% of the measured overlap.
  • ITOT and VO are closer in breadth than a broad-vs-niche ETF pair.
  • 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

ITOT holdings
Mar 12, 2026
VO holdings
Mar 12, 2026
Overlap computed
Mar 15, 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

ITOT

iShares Core S&P Total U.S. Stock Market ETF

Issuer
IShares
Asset class
Equity
Expense ratio
0.03%
AUM
$82B
Inception
Jan 20, 2004

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

ITOT is an equity ETF from IShares, while VO is a mid-cap U.S. equity ETF from Vanguard. ITOT 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 VRT.

02

How They Differ

ITOT is an equity ETF from IShares, while VO is a mid-cap U.S. equity ETF from Vanguard. Neither fund clearly dominates on breadth, so the practical difference is more about weighting, index construction, and cost. ITOT and VO are priced very similarly on expense ratio.

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 3.51% 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

Because ITOT and VO are closer in breadth, the better fit usually comes down to index methodology, issuer preference, and cost. ITOT and VO are priced very similarly on expense ratio.

Overlap Driver Snapshot

Concentration

The top three shared holdings explain 3.51% 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 ITOT and VO.

HoldingITOT Wt.VO Wt.Overlap
NEM0.20%1.31%0.20%
GLW0.16%0.85%0.16%
VRT0.16%0.75%0.16%
HWM0.16%0.89%0.16%
CEG0.15%0.94%0.15%
WDC0.14%0.91%0.14%
WMB0.14%0.44%0.14%
PWR0.13%0.76%0.13%
STX0.13%0.93%0.13%
MRVL0.12%0.36%0.12%

Why These ETFs Overlap

ITOT is an equity ETF from IShares, 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 VRT, which appear in both portfolios and push the overlap score higher.

Holding both ITOT 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 ITOT and VO

What is the overlap between ITOT and VO?+
ITOT and VO currently show an estimated weighted overlap of 14.71% based on the loaded holdings data.
How many holdings do ITOT and VO share?+
They share 272 holdings in the current dataset.
Is the ITOT and VO overlap high?+
The current verdict is Low Overlap. That means the two ETFs have limited duplication in portfolio weight.
Why do ITOT and VO overlap?+
ITOT and VO overlap because the same large positions appear in both funds. In this comparison, the top three shared holdings explain 3.51% of the measured overlap score.
Which ETF is broader, ITOT or VO?+
ITOT and VO look closer in breadth than a broad-vs-niche pair, so the main difference is more about strategy and weighting than simple market coverage.

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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