ETF Overlap: VOO vs QQQ, VTI, VGT, SCHD and VYM
How much do the most popular ETF pairs overlap? Overlap by weight for VOO and QQQ, VOO and VTI, QQQ and VGT, and SCHD and VYM, how each pair moved, and what owning both does.
ToolsGuide
ETF Overlap Checker: How to Check ETF and Fund Overlap
Two ways to see whether your funds are really different: compare what they hold, and compare how they move. The method step by step, a worked sample, and how Exent runs the second check on your whole portfolio.
Key takeaways
- Holdings overlap = the sum, across every stock both funds own, of the smaller of the two weights. Above about 50%, two funds are mostly the same portfolio.
- In Exent’s data (60 months to Sep 30, 2026), QQQ and VGT had a 0.97 correlation, and SPY and VTI had 1.00.
- Funds that overlap fall together: in 2022, QQQ dropped 34.6%, VGT 34.8% and XLK 33.6% peak to trough.
- Exent checks overlap by how your holdings move together, across all your funds and stocks at once, inside the trial.
How do I check ETF overlap?
Compare the two funds’ holdings by weight. For every stock that appears in both, take the smaller of its two weights, then add those numbers up. The total is the share of each fund that is the same money.
- Download each fund’s full holdings list from the issuer’s website, using lists from similar dates.
- Match the stocks that appear in both lists.
- For each match, write down the lower of the two weights.
- Add them up. That sum is the weight‑based overlap.
- Repeat for every pair of funds you own, not just the obvious ones.
Counting shared names is not enough. Two funds can share 400 stocks and still differ a lot if the weights differ, which is why the minimum‑weight method is the standard one. The idea is explained further in ETF overlap and look‑through analysis.
A worked example of the weight method
Illustrative: the top holdings of two made-up large-cap funds.
| Stock (illustrative) | Fund A weight | Fund B weight | Overlap (smaller weight) |
|---|---|---|---|
| Stock 1 | 9% | 12% | 9% |
| Stock 2 | 8% | 11% | 8% |
| Stock 3 | 6% | 9% | 6% |
| Stock 4 | 4% | 0% | 0% |
| Remaining shared stocks | 40% | 25% | 25% |
| Total | 48% |
Illustrative only. Here 48% of each fund is the same exposure. Owning both gives you less diversification than two tickers suggest.
Sample output: how popular ETF pairs moved together
The second check uses prices instead of holdings lists: correlation of monthly returns. A correlation of 1.00 means two funds moved in lockstep. Sample pairs from Exent’s data, 60 months to Sep 30, 2026:
| Pair | Correlation | What it means |
|---|---|---|
| SPY and VTI | 1.00 | Effectively the same exposure |
| QQQ and VUG | 0.98 | Near-duplicate growth exposure |
| QQQ and VGT | 0.97 | Near-duplicate tech exposure |
| QQQ and XLK | 0.96 | Near-duplicate tech exposure |
| SPY and QQQ | 0.92 | Large overlap, QQQ more concentrated |
| SPY and VXUS | 0.80 | Different stocks, still moved together often |
| SPY and GLD | 0.17 | Moved largely independently |
Overlap shows up when markets fall. In the 2022 inflation bear market, QQQ fell 34.6%, VGT 34.8% and XLK 33.6% from peak to trough (Exent’s data). Holding all three gave almost no protection over holding one. See the most common pairs in ETF overlap: common pairs, or individual funds such as QQQ and SPY.
How do I find overlap between my mutual funds?
The same way. Mutual funds publish their holdings in their reports, so the weight method works as long as you compare reports from similar dates. An S&P 500 index mutual fund and an S&P 500 ETF hold the same stocks, so their overlap is close to 100% even though the tickers look unrelated. Correlation catches this too: in Exent’s data, Vanguard’s VFINX index fund moved in line with VTI at a correlation of 1.00.
How Exent checks overlap in your portfolio
Exent measures overlap by behavior, across every holding at once: funds, single stocks and crypto. It does not break funds into their underlying stocks. Instead it calculates the correlation of every pair of holdings over 1, 3 or 5 years and groups the ones that move as one.
- Correlation clusters: groups of holdings that move together, and each cluster’s share of your money.
- Unique positions: “your 12 holdings act like 4 unique positions”, counting each cluster as one.
- The most correlated pairs, strongest first, plus the full correlation matrix.
- Independent holdings: the ones that move on their own.
This catches overlap the weight method misses, for example a tech ETF plus five large tech stocks you also own directly. It runs as part of Portfolio Analysis in the trial. The general guide is Is my portfolio diversified?
Frequently asked questions
Use both checks: the weight-based overlap of the two funds’ holdings, and the correlation of their returns. The first shows shared stocks, the second shows whether the funds behave as one bet.
There is no official limit. As a rough guide, weight-based overlap above about 50%, or a return correlation above about 0.9, suggests two funds are close substitutes.
Almost completely. Both track the S&P 500 index, and in Exent’s data VOO’s correlation with SPY was 1.00.
No. Exent measures overlap by how your holdings move together, which covers funds and single stocks in one view. For the stock-by-stock weight comparison, use the issuers’ holdings lists.
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Educational content, not investment advice. Examples are illustrative; past performance does not guarantee future results.