VOO vs CSPX overlap

Nearly: 96% of the money in VOO and CSPX sits in the same companies at the same weights, as of August 31, 2026. The other 3.9% is weight differences, plus 8 names only in VOO and 7 only in CSPX.

96% by weight, as of August 31, 2026: nearly the same fund. 497 companies appear in both funds; they make up 100% of VOO and 99% of CSPX.

The largest shared positions are NVDA, AAPL, MSFT, AMZN and GOOGL. Ranked by the smaller of the two weights, which is the part you would own twice.

Out of every $100 split evenly between them, about $96 (half in each fund) buys identical positions. The rest is exposure only one of the two funds gives you: 8 names only in VOO, 7 only in CSPX. Half in each behaves like 45 equally weighted stocks, against 46 for VOO alone and 44 for CSPX alone. Whether that duplication is a problem depends on the mix you want; this is a description, not advice.

Close to it: 96% of the money in CSPX and VOO sits in the same companies at the same weights, as of August 31, 2026. CSPX is iShares Core S&P 500 UCITS ETF (ISIN IE00B5BMR087), an Irish-domiciled UCITS fund on the S&P 500 index. European brokers generally don't sell US-listed ETFs such as VOO to retail clients, because those funds publish no KID (the PRIIPs key information document); UCITS funds do.

Yes. CSPX also trades as CSP1 (London, GBP), SXR8 (Xetra, EUR) and CSSPX (Borsa Italiana, EUR). Each is the same portfolio in another currency, on another exchange or paying its dividends out, so VOO vs SXR8 also overlaps 96%.

For every company held by both funds we take the smaller of its two weights and add them up. The weights come from the full holdings files Vanguard and iShares publish, not a top-10 sample, and companies are matched by their ISIN so share classes stay apart. Sector overlap applies the same rule to the issuers' sector labels; "behaves like N equally weighted stocks" is one over the sum of the squared weights.