etf overlap · heavy overlap
SPY vs IWF overlap
59% of SPY and IWF is the same money, spread over 179 companies both funds hold.
Holdings as of September 24, 2026 · source: SPDR (SPY), iShares (IWF) · How we measured all 1,035 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 IWF: what people ask
How much do SPY and IWF overlap?
59% by weight, as of September 24, 2026: heavy overlap. 179 companies appear in both funds; they make up 68% of SPY and 94% of IWF.
Which stocks do SPY and IWF both hold?
The largest shared positions are NVDA, AAPL, MSFT, GOOGL and META. Ranked by the smaller of the two weights, which is the part you would own twice.
Is it redundant to hold both SPY and IWF?
Out of every $100 split evenly between them, about $59 (half in each fund) buys identical positions. The rest is exposure only one of the two funds gives you: 325 names only in SPY, 192 only in IWF. Half in each behaves like 30 equally weighted stocks, against 44 for SPY alone and 20 for IWF alone. Whether that duplication is a problem depends on the mix you want; this is a description, not advice.
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.