IWB vs SPLG Overlap
IWB is an equity ETF from IShares, while SPLG is a U.S. large-cap core ETF from SPDR. IWB and SPLG show very heavy overlap, with an estimated weighted overlap of 85.55%. They share 471 holdings in the loaded dataset, led by NVDA, AAPL, and MSFT.
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Quick Answer
IWB is an equity ETF from IShares, while SPLG is a U.S. large-cap core ETF from SPDR. IWB and SPLG show very heavy overlap, with an estimated weighted overlap of 85.55%. They share 471 holdings in the loaded dataset, led by NVDA, AAPL, and MSFT.
- 85.55% weighted overlap across 471 shared holdings.
- The top three shared holdings explain 20.91% of the measured overlap.
- SPLG is the broader fund, while IWB 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
- IWB holdings
- Mar 12, 2026
- SPLG 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
What Stands Out In This Comparison
What This Means
IWB is an equity ETF from IShares, while SPLG is a U.S. large-cap core ETF from SPDR. IWB and SPLG are closely aligned. A large share of their portfolio weight is invested in the same companies, especially NVDA, AAPL, and MSFT, which means holding both is likely to feel similar to increasing the size of one core position.
How They Differ
IWB is an equity ETF from IShares, while SPLG is a U.S. large-cap core ETF from SPDR. SPLG is the broader fund, while IWB is the more targeted sleeve. SPLG has the lower expense ratio, while IWB 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 20.91% 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, SPLG is usually the wider choice. If you want the more focused tilt, IWB is the narrower expression. SPLG has the lower expense ratio, while IWB charges more for its exposure.
Overlap Driver Snapshot
Concentration
The top three shared holdings explain 20.91% 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 IWB and SPLG.
| Holding | Name | IWB Wt. | SPLG Wt. | Overlap |
|---|---|---|---|---|
| NVDA | NVIDIA CORP | 6.95% | 8.34% | 6.95% |
| AAPL | APPLE INC | 6.11% | 6.79% | 6.11% |
| MSFT | MICROSOFT CORP | 4.83% | 6.85% | 4.83% |
| AMZN | AMAZON COM INC | 3.30% | 3.78% | 3.30% |
| GOOGL | ALPHABET INC CLASS A | 2.87% | 2.64% | 2.64% |
| AVGO | BROADCOM INC | 2.54% | 2.98% | 2.54% |
| META | META PLATFORMS INC CLASS A | 2.29% | 2.77% | 2.29% |
| GOOG | ALPHABET INC CLASS C | 2.33% | 2.13% | 2.13% |
| TSLA | TESLA INC | 1.81% | 2.20% | 1.81% |
| BRK-B | BERKSHIRE HATHAWAY INC CLASS B | 1.46% | 1.50% | 1.46% |
Why These ETFs Overlap
IWB is an equity ETF from IShares, while SPLG 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 NVDA, AAPL, and MSFT, which appear in both portfolios and push the overlap score higher.
Holding both IWB and SPLG is usually redundant unless you have a very specific reason to tilt toward their shared holdings. In most cases, one ETF is enough.
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Frequently Asked Questions About IWB and SPLG
What is the overlap between IWB and SPLG?+
How many holdings do IWB and SPLG share?+
Is the IWB and SPLG overlap high?+
Why do IWB and SPLG overlap?+
Which ETF is broader, IWB or SPLG?+
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.