etf overlap · nearly the same fund
SPY vs CSPX overlap
97% of SPY and CSPX is the same money, spread over 500 companies both funds hold.
Holdings as of September 24, 2026 · source: SPDR (SPY), iShares (CSPX) · How we measured all 1,431 pairs
- same money
- same companies, extra weight
- only in this fund
The companies you would own twice
What only one of them gives you
Where each fund puts its money
SPY and CSPX: what people ask
Is CSPX the same as SPY?
Nearly: 97% of the money in SPY and CSPX sits in the same companies at the same weights, as of September 24, 2026. The other 2.6% is weight differences, plus 4 names only in SPY and 4 only in CSPX.
How much do SPY and CSPX overlap?
97% by weight, as of September 24, 2026: nearly the same fund. 500 companies appear in both funds; they make up 100% of SPY and 100% of CSPX.
Which stocks do SPY and CSPX both hold?
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.
Is it redundant to hold both SPY and CSPX?
Out of every $100 split evenly between them, about $97 (half in each fund) buys identical positions. The rest is exposure only one of the two funds gives you: 4 names only in SPY, 4 only in CSPX. Half in each behaves like 44 equally weighted stocks, against 44 for SPY alone and 44 for CSPX alone. Whether that duplication is a problem depends on the mix you want; this is a description, not advice.
Is CSPX the European version of SPY?
Close to it: 97% of the money in CSPX and SPY sits in the same companies at the same weights, as of September 24, 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 SPY to retail clients, because those funds publish no KID (the PRIIPs key information document); UCITS funds do.
Does the SPY vs CSPX overlap apply to other tickers?
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 SPY vs SXR8 also overlaps 97%.
How is ETF overlap calculated here?
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 SPDR 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.
Weights come from each issuer's published holdings file and are matched company by company on their ISIN. Cash, futures and currency positions are left out. This page describes what the funds hold; it is not investment advice.