etf overlap tool · moderate overlap
XLK vs CSPX overlap
99.9% of XLK's money sits in companies CSPX also holds; 38% of the two funds is the same money, spread over 75 companies both hold.
Holdings as of October 16, 2026 · source: SPDR (XLK), iShares (CSPX) · How we measured all 1,431 pairs
- same money
- same companies, extra weight
- only in this fund
Hold XLK and CSPX with other funds or stocks? The free portfolio optimizer opens XLK and CSPX beside the rest of what you own: the companies you hold twice, what the funds cost a year, and where the next deposit should go. No account.
The companies you would own twice
What only one of them gives you
Every XLK holding is also in the other fund.
AMZNAMAZON.COM INC3.72%Where each fund puts its money
XLK and CSPX: what people ask
How much do XLK and CSPX overlap?
38% by weight, as of October 16, 2026: moderate overlap. 75 companies appear in both funds; they make up 99.9% of XLK and 38% of CSPX.
Which stocks do XLK and CSPX both hold?
The largest shared positions are NVDA, AAPL, MSFT, AVGO and MU. Ranked by the smaller of the two weights, which is the part you would own twice.
Is it redundant to hold both XLK and CSPX?
Out of every $100 split evenly between them, about $38 (half in each fund) buys identical positions. The rest is exposure only one of the two funds gives you: 0 names only in XLK, 428 only in CSPX. Half in each behaves like 25 equally weighted stocks, against 14 for XLK alone and 44 for CSPX alone. Whether that duplication is a problem depends on the mix you want; this is a description, not advice.
What is CSPX, next to XLK?
CSPX is iShares Core S&P 500 UCITS ETF (ISIN IE00B5BMR087), an Irish-domiciled UCITS fund on the S&P 500 index. Next to XLK, 38% of the money is the same, spread over 75 companies both hold, as of October 16, 2026.
Does the XLK 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 XLK vs SXR8 also overlaps 38%.
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.