CSPX vs VOO ETF holdings comparison
iShares Core S&P 500 UCITS ETF (USD Acc) (CSPX) · Vanguard S&P 500 ETF (VOO)
CSPX and VOO overlap by 91% by portfolio weight. The remaining 9.0 percentage points are not counted as shared holdings weight by this calculation. They share 494 stocks; the largest shared position is Nvidia (NVDA), contributing 7.51% to the overlap.
The holdings dates differ. This can slightly understate overlap for funds tracking similar indexes.
What this means
CSPX and VOO share most of their portfolio weight in the same underlying stocks. OverlapCheck labels this "high holdings overlap" using house ranges of 70% or more, 30% to under 70%, and under 30%. These descriptive ranges are not industry standards or investment guidance. Holdings overlap does not measure correlation, volatility, geographic or factor exposure, fees, or suitability.
Overlap by weight sums the smaller of the two funds' weights for every stock they both hold. It answers "how much of my money is in the same stocks either way?" See methodology.
This comparison covers normalized equity positions represented in the dataset. Cash, derivatives, options, structured notes, and other non-equity assets are not included, so the result is not a complete comparison of every asset or risk in either fund.
Top shared holdings
| Company | Ticker | in CSPX | in VOO |
|---|---|---|---|
| Nvidia | NVDA | 8.07% | 7.51% |
| Apple | AAPL | 7.02% | 6.59% |
| Microsoft | MSFT | 5.69% | 4.30% |
| Amazon.Com Inc | AMZN | 3.84% | 3.62% |
| Alphabet Class A | GOOGL | 3.00% | 3.25% |
| Broadcom Inc | AVGO | 2.65% | 2.77% |
| Alphabet Class C | GOOG | 2.39% | 2.59% |
| Meta Platforms Class A | META | 1.90% | 1.92% |
| Micron Technology | MU | 1.63% | 2.02% |
| Tesla Inc | TSLA | 1.56% | 1.84% |
Holdings only in CSPX or VOO
CSPX has 9 fund-only positions representing approximately 2.6 percentage points of reported exposure; VOO has 10 fund-only positions representing approximately 2.5 percentage points of reported exposure. These are positions whose normalized security identifiers appear in one issuer file but not the other.
Largest positions only in CSPX
| Company | Ticker | Weight |
|---|---|---|
| Berkshire Hathaway Inc Class B | BRKB | 1.39% |
| Exxonmobil Holdings Corp | XOM | 1.01% |
| Vivmark Residential | VMRK | 0.07% |
| Ferguson Enterprises Inc | FERG | 0.07% |
| Amcor Plc | AMCR | 0.03% |
| Keycorp | KEY | 0.03% |
| Reddit Class A | RDDT | 0.03% |
| Alexandria Real Estate Equities Re | ARE | 0.01% |
| Brown Forman Class B | BFB | 0.01% |
Largest positions only in VOO
| Company | Ticker | Weight |
|---|---|---|
| Berkshire Hathaway Inc | BRK.B | 1.42% |
| Exxon Mobil Corp | XOM | 0.88% |
| Electronic Arts Inc | EA | 0.07% |
| AvalonBay Communities Inc | AVB | 0.04% |
| Equity Residential | EQR | 0.04% |
| KeyCorp | KEY | 0.03% |
| Amcor PLC | N/A | 0.03% |
| Alexandria Real Estate Equities Inc | ARE | 0.01% |
| Conagra Brands Inc | CAG | <0.01% |
| Brown-Forman Corp | BF.B | <0.01% |
FAQ
How much do CSPX and VOO overlap?
CSPX and VOO have 91% overlap by weight, sharing 494 equity positions (out of 503 in CSPX and 504 in VOO). The official holdings files used are dated 2026-08-31 for CSPX and 2026-06-30 for VOO.
What does 91% overlap mean?
CSPX and VOO share most of their portfolio weight in the same underlying stocks. OverlapCheck labels this "high holdings overlap" using house ranges of 70% or more, 30% to under 70%, and under 30%. These descriptive ranges are not industry standards or investment guidance. Holdings overlap does not measure correlation, volatility, geographic or factor exposure, fees, or suitability.
Which stocks do CSPX and VOO both hold?
The largest shared positions are Nvidia, Apple, Microsoft, Amazon.Com Inc, Alphabet Class A. The top shared holdings with weights in each fund are shown on this page.
What holdings are different between CSPX and VOO?
CSPX has 9 positions not found in VOO, while VOO has 10 positions not found in CSPX. The largest fund-only positions and their weights are shown on this page.
Related comparisons
One side of this pair is a UCITS ETF. How share classes and listings map to one fund, and which popular UCITS combinations repeat the same US mega-caps, is covered in ETF overlap for European investors.