IWD vs SPY Overlap
IWD is a U.S. value equity ETF from IShares, while SPY is a U.S. large-cap core ETF from SPDR. IWD and SPY show heavy overlap, with an estimated weighted overlap of 51.32%. They share 401 holdings in the loaded dataset, led by GOOGL, AMZN, and GOOG.
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Quick Answer
IWD is a U.S. value equity ETF from IShares, while SPY is a U.S. large-cap core ETF from SPDR. IWD and SPY show heavy overlap, with an estimated weighted overlap of 51.32%. They share 401 holdings in the loaded dataset, led by GOOGL, AMZN, and GOOG.
- 51.32% weighted overlap across 401 shared holdings.
- The top three shared holdings explain 10.78% of the measured overlap.
- SPY is the broader fund, while IWD is more targeted.
- The overlap is mostly explained by the top shared positions rather than sector labels alone.
- Holding both may add less diversification than the fund names imply.
Data Freshness
- IWD holdings
- Mar 12, 2026
- SPY 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
What Stands Out In This Comparison
What This Means
IWD is a U.S. value equity ETF from IShares, while SPY is a U.S. large-cap core ETF from SPDR. IWD and SPY share a large chunk of the same portfolio weight. The overlap is driven by positions like GOOGL, AMZN, and GOOG, so owning both may not diversify your stock exposure as much as the fund names suggest.
How They Differ
IWD is a U.S. value equity ETF from IShares, while SPY is a U.S. large-cap core ETF from SPDR. SPY is the broader fund, while IWD is the more targeted sleeve. SPY has the lower expense ratio, while IWD charges more for its exposure.
What Drives The Overlap
The overlap is driven by a relatively small set of large shared positions. The top three shared holdings account for 10.78% of the score, which means the result is heavily influenced by the biggest common weights rather than a long tail of tiny positions.
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, IWD is the narrower expression. SPY has the lower expense ratio, while IWD charges more for its exposure.
Overlap Driver Snapshot
Concentration
The top three shared holdings explain 10.78% 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 IWD and SPY.
| Holding | Name | IWD Wt. | SPY Wt. | Overlap |
|---|---|---|---|---|
| GOOGL | ALPHABET INC CLASS A | 2.04% | 3.08% | 2.04% |
| AMZN | AMAZON COM INC | 1.82% | 3.59% | 1.82% |
| GOOG | ALPHABET INC CLASS C | 1.66% | 2.46% | 1.66% |
| BRK-B | BERKSHIRE HATHAWAY INC CLASS B | 2.94% | 1.56% | 1.56% |
| JPM | JPMORGAN CHASE & CO | 2.53% | 1.35% | 1.35% |
| XOM | EXXON MOBIL CORP | 2.02% | 1.08% | 1.08% |
| JNJ | JOHNSON & JOHNSON | 1.89% | 1.01% | 1.01% |
| WMT | WALMART INC | 1.58% | 0.94% | 0.94% |
| META | META PLATFORMS INC CLASS A | 0.82% | 2.45% | 0.82% |
| MU | MICRON TECHNOLOGY INC | 1.45% | 0.78% | 0.78% |
Why These ETFs Overlap
IWD is a U.S. value equity ETF from IShares, while SPY is a U.S. large-cap core ETF from SPDR. The overlap exists because both funds allocate meaningful weight to the same holdings. In this dataset, the biggest shared drivers are GOOGL, AMZN, and GOOG, which appear in both portfolios and push the overlap score higher.
Holding both IWD and SPY may add less diversification than you expect. Many investors would choose the ETF that best matches their goal and avoid paying for duplicate exposure.
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Frequently Asked Questions About IWD and SPY
What is the overlap between IWD and SPY?+
How many holdings do IWD and SPY share?+
Is the IWD and SPY overlap high?+
Why do IWD and SPY overlap?+
Which ETF is broader, IWD or SPY?+
How Overlap Is Calculated
A straightforward approach used by portfolio analysts.
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.