IWR vs VOO Overlap

IWR is a mid-cap U.S. equity ETF from IShares, while VOO is a U.S. large-cap core ETF from Vanguard. IWR and VOO show limited overlap, with an estimated weighted overlap of 13.56%. They share 291 holdings in the loaded dataset, led by WDC, BK, and HWM.

13.6% overlap
#
291Shared Holdings
OK
Low Overlap

Served from cache.

Quick Answer

IWR is a mid-cap U.S. equity ETF from IShares, while VOO is a U.S. large-cap core ETF from Vanguard. IWR and VOO show limited overlap, with an estimated weighted overlap of 13.56%. They share 291 holdings in the loaded dataset, led by WDC, BK, and HWM.

  • 13.56% weighted overlap across 291 shared holdings.
  • The top three shared holdings explain 3.14% of the measured overlap.
  • VOO is the broader fund, while IWR 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

IWR holdings
Mar 12, 2026
VOO holdings
Mar 12, 2026
Overlap computed
Mar 13, 2026
Data source
Financial Modeling Prep

Review the methodology for the overlap formula and refresh policy.

Compare another pair

vs

About These ETFs

ETF A

IWR

iShares Russell Mid-Cap ETF

Issuer
IShares
Asset class
Equity
Expense ratio
0.18%
AUM
$48B
Inception
Jul 17, 2001

ETF B

VOO

Vanguard S&P 500 ETF

Issuer
Vanguard
Asset class
Large Cap Equity
Expense ratio
0.03%
AUM
$2T
Inception
Sep 7, 2010

What Stands Out In This Comparison

01

What This Means

IWR is a mid-cap U.S. equity ETF from IShares, while VOO is a U.S. large-cap core ETF from Vanguard. IWR and VOO 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 WDC, BK, and HWM.

02

How They Differ

IWR is a mid-cap U.S. equity ETF from IShares, while VOO is a U.S. large-cap core ETF from Vanguard. VOO is the broader fund, while IWR is the more targeted sleeve. VOO has the lower expense ratio, while IWR 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 3.14% 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, VOO is usually the wider choice. If you want the more focused tilt, IWR is the narrower expression. VOO has the lower expense ratio, while IWR charges more for its exposure.

Overlap Driver Snapshot

Concentration

The top three shared holdings explain 3.14% 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 IWR and VOO.

HoldingIWR Wt.VOO Wt.Overlap
WDC0.70%0.14%0.14%
BK0.63%0.14%0.14%
HWM0.79%0.14%0.14%
GLW0.83%0.14%0.14%
CMI0.60%0.14%0.14%
SNDK0.68%0.14%0.14%
HOOD0.45%0.13%0.13%
PWR0.65%0.12%0.12%
COR0.50%0.12%0.12%
HLT0.53%0.12%0.12%

Why These ETFs Overlap

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

Holding both IWR and VOO 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 IWR and VOO

What is the overlap between IWR and VOO?+
IWR and VOO currently show an estimated weighted overlap of 13.56% based on the loaded holdings data.
How many holdings do IWR and VOO share?+
They share 291 holdings in the current dataset.
Is the IWR and VOO overlap high?+
The current verdict is Low Overlap. That means the two ETFs have limited duplication in portfolio weight.
Why do IWR and VOO overlap?+
IWR and VOO overlap because the same large positions appear in both funds. In this comparison, the top three shared holdings explain 3.14% of the measured overlap score.
Which ETF is broader, IWR or VOO?+
VOO is the broader fund, while IWR 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.

Looking for another pair? Start from the homepage or open the canonical URL for this comparison at /compare/IWR-VOO.