etf overlap · heavy overlap
SPY vs MGK overlap
52% of SPY and MGK is the same money, spread over 50 companies both funds hold.
Holdings as of September 24, 2026 · source: SPDR (SPY), Vanguard (MGK) · 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 MGK: what people ask
How much do SPY and MGK overlap?
52% by weight, as of September 24, 2026: heavy overlap. 50 companies appear in both funds; they make up 52% of SPY and 99% of MGK.
Which stocks do SPY and MGK 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 MGK?
Out of every $100 split evenly between them, about $52 (half in each fund) buys identical positions. The rest is exposure only one of the two funds gives you: 454 names only in SPY, 2 only in MGK. Half in each behaves like 26 equally weighted stocks, against 44 for SPY alone and 17 for MGK 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 Vanguard 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.