How do I check ETF overlap in my portfolio?
November 6, 2026
ETF overlap becomes a problem when multiple funds leave you with more exposure to certain companies or sectors than you intended. To check, look at the holdings across your ETFs, account for how much you’ve invested in each, and compare your overall exposure with a total-market fund. The three metrics and examples below will help you spot potential concentrations in your portfolio.
How much ETF overlap is too much?
A common rule of thumb is that two funds with overlap below about 20% add diversification, while funds with overlap above about 50% mostly do the same job. Between those levels, check what each fund adds to your portfolio and whether that matches why you own it.
This rule only tells you how similar two funds are. To assess overlap across your whole portfolio, use the three checks below to compare your company and sector weights with the market.
| Fund pair | Overlap by weight | What it means |
|---|---|---|
| SPY and VOO | 99% | Both track the same index, so holding both adds no diversification. |
| VTI and VOO | 88% | VTI also holds mid- and small-cap stocks, which make up about 12% of the fund. |
| VOO and QQQ | 52% | QQQ increases your technology exposure and excludes financials. |
| SCHD and VYM | 23% | Both hold dividend stocks, but they use different criteria to select them. |
| VTI and SCHD | 8% | Even with low overlap, adding SCHD changes how much you have invested in each sector. |
The check: three numbers for your whole portfolio
List all the stocks and funds you own across your accounts and how much you’ve invested in each. Then check which companies your funds have in common.
The impact of overlap depends on how much money you have in each fund. For example, even 90% overlap may have little effect if one fund makes up just 3% of your portfolio. But 40% overlap between your two largest funds could leave you with too much money invested in the same companies.
Your weight in each company, compared with the market
The check: for each company, add up how much you own directly and through your funds. Compare that with the company’s weight in a total-market fund such as VTI, and flag any company where your weight is more than 1.5 times its market weight.
Why it matters: a total-market fund holds every company at its market size. A weight well above that is an extra bet on one company, often picked up because several of your funds hold it rather than chosen on purpose.
What to do: for each flagged company, decide whether you want the extra weight. If you don’t, find which of your funds adds most of it and lower your position in that fund.
Your top 10 holdings combined, compared with the market’s top 10
The check: add up the weights of your ten largest company holdings, including the companies you own through funds. Compare the total with the total market’s top 10, around 36% as of November 2, 2026.
Why it matters: if your top 10 is more than about 10 percentage points above the market’s, your portfolio behaves like a concentrated large-cap growth fund. That concentration may be hard to spot from the fund names alone.
What to do: look at which funds hold your largest companies. If two of your bigger funds hold the same large companies, they add to the concentration.
Your sector weights, compared with the market
The check: compare each sector’s share of your portfolio with its share of the total market (VTI).
Why it matters: overlap between funds usually leaves you overweight in a sector, most often technology. For example, as of November 2, 2026, a portfolio split equally between VOO and QQQM has 49% in technology, compared with 38% for the total market. That portfolio will fall harder in a tech sell-off than you might expect from looking at the fund names.
What to do: check both the largest overweights and the largest underweights. Underweights also change how your portfolio does compared with the market.
Tools to check ETF overlap
- Free overlap calculators: Enter two or more tickers in a tool such as ETF Research Center or etf-overlap.com to see their overlap percentage. These tools give you a quick comparison of funds. They don’t account for how much you have invested in each fund or compare your portfolio with the market.
- Koyfin: See every stock you own through your funds, which funds hold it and its total weight in your portfolio. Then compare your sector, country and style exposure with a benchmark.
Where overlap checks go wrong, and how to avoid it
Before deciding whether to keep, add, or remove a fund, compare your overall portfolio with the market. Looking at overlap between two funds alone can miss concentrations in certain stocks or sectors, as in the three cases below.
Overlap scores leave out what a fund doesn’t hold
The check: compare your portfolio’s sector weights with the total market and look at the underweights as well as the overweights.
Why the overlap score misses it: an overlap score may not show you which sectors become underweight when you add a fund. Underweights also affect your returns relative to the benchmark.
For example, VOO and QQQM overlap by about 52% by weight. Adding QQQM increases your exposure to the companies both funds hold and to technology. It also changes your sector exposure because the Nasdaq-100 excludes financial companies by rule and holds almost no energy stocks.
As of November 2, 2026:
| Portfolio | Financials |
|---|---|
| 50/50 VOO and QQQM | 5.7% |
| Total market (VTI) | 11.5% |
With half as much exposure to banks and insurers, your portfolio can lag when those companies lead the market.
What to do: in Koyfin’s portfolio tools, open the Exposure tab, switch to Vs. Benchmark, sort by Over/Under Weight and check both the top and bottom of the list.
Low overlap can come with large sector overweights
The check: see how adding the fund changes your sector weights compared with the market. If the largest overweights and underweights differ from your intended allocation, reconsider the fund’s role in your portfolio.
Why overlap calculators miss it: VTI and SCHD overlap by only about 8% by weight, so overlap calculators suggest that SCHD offers good diversification. SCHD holds about 100 dividend-paying companies selected using dividend history and quality screens, so it holds much less technology and much more energy and consumer staples than VTI. An overlap score doesn’t show that change in sector exposure.
As of November 2, 2026:
| Sector | VTI | 70% VTI and 30% SCHD | Change |
|---|---|---|---|
| Technology | 38.1% | 31.6% | Down about 6.5 points |
| Energy | 3.6% | 7.4% | Roughly doubles |
| Consumer staples | 4.2% | 8.8% | Roughly doubles |
What to do: check how the fund changes your sector exposure in the Vs. Benchmark view on the Exposure tab of Koyfin’s portfolio tools. Use the Holdings Contribution table to see how each fund contributes to your overweights and underweights.
Funds with little overlap can still fall together
The check: compare how the fund and your other funds did in 2022. If two funds fell within a few points of each other, treat them as one position when deciding how much to invest.
Why the overlap score misses it: funds with different holdings can share the same risks during a sell-off. QQQM, a semiconductor fund such as SMH and an innovation fund such as ARKK share few holdings by weight. All three hold companies whose stock prices depend on the profits investors expect them to earn years in the future. Those companies faced the same risk from rising interest rates, which caused all three funds to fall.
From the first trading day of 2022 to the end of that year, including dividends:
| Fund | 2022 fall |
|---|---|
| QQQM | About 33% |
| SMH | About 35% |
| ARKK | About 68% |
| SPY, an S&P 500 fund | About 19% |
What to do: before you count on a fund to diversify your portfolio, compare it with your other funds on a Koyfin chart starting at the beginning of 2022.
Koyfin’s Holdings Matrix shows each stock’s total weight in your portfolio, how many of your funds hold it, and how much comes from each fund and from shares you own directly. It’s available for personal, model and client portfolios. For example, Nvidia makes up 8.2% of a portfolio split equally between VOO and QQQM, with 4.2% held through VOO and 4.0% through QQQM.
What the check shows for a common three-fund portfolio
For example, here’s how the check works for a portfolio split equally between VTI, SCHD and QQQM. The table compares its exposure with VTI alone as of the November 2, 2026 close, using a model portfolio in Koyfin’s portfolio tools.
| Measure | VTI + SCHD + QQQM (1/3 each) | VTI alone |
|---|---|---|
| Top 10 holdings combined | 28.9% | 36.0% |
| Technology | 37.5% | 38.1% |
| Largest single company | Nvidia, 5.0% | Nvidia, 7.1% |
| Companies above 1.5x their market weight | 82 of the 136 holdings at 0.1% or more | – |
Adding SCHD and QQQM lowers the weight of the 10 largest companies but barely changes technology, because QQQM adds back most of the tech weight that SCHD leaves out. The bigger shift is in the sectors SCHD favors: consumer staples rise from 4.2% to 10.2% and energy from 3.6% to 6.8%, while financials fall from 11.5% to 6.9%. Most of the 82 overweight companies are SCHD’s dividend payers, such as Texas Instruments at 2.1% of the portfolio against 0.4% of VTI.
Figures as of November 2, 2026, for research purposes only. Alphabet’s two share classes are counted as one company.
Check your own portfolio
Create a free Koyfin account and add your stocks and funds to My Portfolio. The Holdings Matrix shows your total weight in each company across all your funds. Compare it with each company’s weight on VTI’s holdings page. The Exposure tab then compares your sector weights with VTI or another benchmark. New accounts get 7 days of full access.
If you’re a financial advisor, run the same checks on a model portfolio or on a client or prospect household, brought in from your custodian or from a PDF statement. Then turn the results into a client report or proposal.
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Common questions about ETF overlap
Is ETF overlap bad?
Overlap is fine when you choose it deliberately, for example when you hold the same S&P 500 fund in two accounts. It becomes a problem when it puts more of your money in the same companies or sector than you planned.
How do you measure overlap between two ETFs?
For each stock the two ETFs have in common, use the smaller of its two weights. Add those weights together to get the overlap percentage. Counting shared holdings can be misleading because two funds can share hundreds of small positions and still have very different exposure.
How many ETFs is too many?
There’s no fixed number of ETFs to own, so add a fund only if it increases your exposure to investments you want more of. If it mostly repeats your largest holdings, it adds cost and complexity without improving diversification.
Does overlap matter if both funds are cheap?
Yes, overlap matters even with low fees if both funds invest heavily in the same five companies. When those companies fall, the concentration leads to a bigger drawdown in your portfolio.
Can I check mutual fund overlap the same way?
You can check mutual fund overlap using the same three metrics. Treat the results as approximate because mutual funds publish full holdings only quarterly, up to 60 days after quarter end, so an active fund’s holdings can be four or five months old.
Checking ETF overlap in Koyfin
Can I compare two specific funds for overlap in Koyfin?
Add both funds to My Portfolio or a model portfolio and open the Holdings Matrix. It shows each stock’s weight in each fund side by side, so you can see which holdings the funds share.
Can advisors check overlap across a client’s household?
Yes. In Client Portfolios, group the client’s accounts into a household. The household’s Holdings Matrix shows the client’s total weight in each company across all accounts and funds, and its Exposure tab shows the household’s sector, country and style weights.
Editorial note
Our insights are derived solely from historical information and analyst predictions, employing an impartial approach. Please note that our articles do not serve as financial guidance.