ETF Overlap Tool
Free ETF Overlap & Fee Drag Calculator — Compare Any Two ETFs
Compare two ETFs side by side. See shared holdings, portfolio overlap percentage, fee drag, and the estimated extra annual cost based on your investment amount. Built for beginners. No signup.
What is ETF overlap?
ETF overlap is when two ETFs hold many of the same stocks. If you own both, you might think you have a diversified portfolio, but in reality a big chunk of your money is in the same companies twice. The calculator shows you exactly how much overlap exists and how much extra you are paying in fees on those duplicate holdings.
Why does ETF overlap matter?
Patterns that hold across every reporting season. The specific numbers change, the structure does not.
Compare Two ETFs
Select two ETFs, enter your investment amount, then compare overlap, shared holdings and potential fee drag.
Overlap: —
Fee Drag: —
Extra Fees Per Year: —
| Holding | ETF 1 % | ETF 2 % |
|---|
Educational content only. Holdings data is stored and updated periodically. Results may not reflect the most current fund compositions. Always verify current holdings, fees and product data directly with the ETF provider before making any investment decision.
The ETF Overlap & Fee Drag Calculator takes two ETFs and shows you exactly how similar they are. It calculates the percentage overlap in holdings, identifies the shared stocks, and estimates how much extra you are paying in fees when both funds hold the same companies.
How to use the ETF Overlap & Fee Drag Calculator — written walkthrough
A four-stage written walkthrough — how to enter two ETFs, read shared holdings and understand fee drag.
How a beginner should approach this tool
Each chapter below maps to a stage of using this tool — work through them in order.
- Step 1Entering two ETF tickers
- Step 2Reading overlap percentage
- Step 3Comparing expense ratios
- Step 4When overlap and fee drag matter
Why should you check ETF overlap?
Clear beginner outcomes for this specific tool.
Avoid accidental duplication
Two ETFs can own many of the same stocks, creating less diversification than expected.
See hidden concentration
Overlap shows whether a portfolio is really diversified or just repeating the same mega caps.
Compare fee drag
Expense ratios matter more when two funds provide similar exposure.
What is ETF overlap and why does fee drag matter?
ETF overlap is the silent killer of “diversified” retail portfolios. People buy 5 funds thinking they are spreading risk, then find out 70% of their money is in the same 20 stocks. Fee drag compounds the problem: even tiny percentage differences in expense ratios cost thousands over a decade.
- ETF overlap is when two ETFs hold many of the same stocks. Large-cap US ETFs often share 80%+ of their holdings.
- Fee drag is the cost of higher expense ratios over time. Even 0.5% per year compounds to thousands over decades.
- Owning multiple overlapping ETFs is not diversification. You are paying twice for the same exposure.
- The calculator gives you an overlap percentage and an estimated extra annual fee cost based on your investment amount.
- Some overlap is fine when it is intentional. The point of the tool is to make overlap visible so you can decide.
Total read time: about 8 minutes. Each section can stand on its own.
What is ETF overlap? 1 min read
ETF overlap compares the holdings two funds share. SPY and VOO both track the S&P 500, so they generally hold many of the same companies; a fund following a different index can hold fewer of them. Check the underlying holdings and their weights rather than assuming a fixed overlap from the fund names.
Why this matters: two ETFs with high holdings overlap may add less diversification than their names suggest. Each expense ratio applies to the dollars allocated to that fund, so compare distinct holdings, weights, and costs before drawing a conclusion.
- 0 to 20% overlap — meaningful diversification
- 20 to 50% overlap — partial overlap, some diversification
- 50 to 80% overlap — heavy overlap, limited diversification
- 80 to 100% overlap — almost identical, paying twice for the same exposure
How fee drag compounds 1 min read
Fee drag is the cumulative cost of paying expense ratios year after year. The number sounds small in any single year but the compounding is real.
Example: $50,000 invested for 20 years, 7% average annual return.
0.03% fee ETF (like VOO): final value roughly $193,000. Lifetime fees roughly $850.
0.95% fee ETF (like an active fund): final value roughly $162,000. Lifetime fees roughly $14,500.
Same underlying market exposure. The investor in the lower-fee ETF keeps $31,000 more, all from a 0.92% per year difference. That is the math the calculator surfaces.
Common overlapping ETF pairs 1 min read
ETFs that look different but are actually very similar
The lesson: ETF names imply distinct exposures. The actual holdings often tell a different story. Always check the overlap before assuming two funds give you diversification.
How to read the holdings comparison 1 min read
The output table shows each shared holding with its weight in both ETFs. The right column flags whether the stock is in both funds, ETF 1 only, or ETF 2 only.
| What you see | What it means | What to do |
|---|---|---|
| OVERLAP tag | Both ETFs hold this stock | Sum the two weights to see your total exposure |
| ETF 1 ONLY tag | This is what makes ETF 1 different | If you keep both ETFs, this is what you gain by holding ETF 1 |
| ETF 2 ONLY tag | This is what makes ETF 2 different | If you keep both ETFs, this is what you gain by holding ETF 2 |
| Overlap % | Combined weight of shared holdings | Higher = less real diversification from owning both |
If the “unique to each ETF” stocks make up less than 20% of either fund, owning both is mostly fee duplication.
Common mistakes when comparing ETFs 2 min read
Assuming different names mean different exposures. SPY and IVV are both S&P 500 trackers. Their names are different. Their holdings are the same.
→ Fix: Always check overlap before adding a “different” ETF to a portfolio.
Ignoring expense ratios because the numbers look small. 0.03% sounds the same as 0.50%. Over 20 years on $100,000, the difference is roughly $35,000.
→ Fix: Use the calculator to see the real lifetime cost of each fee. Then choose the cheapest fund with the exposure you actually want.
Thinking 5 ETFs equals diversification. If all 5 ETFs are US large-cap tech-heavy funds, you have one position in five wrappers.
→ Fix: Compare every ETF in your portfolio against each other. Real diversification requires intentional exposure to different markets, sectors, or sizes.
Picking the most expensive S&P 500 ETF by mistake. There are dozens. They differ in fees from 0.03% to nearly 1%. The holdings are essentially identical.
→ Fix: When two ETFs track the same index, fees are the only meaningful difference. Always go cheap.
Forgetting that overlap changes over time. Active and smart-beta ETFs change holdings. Overlap today may differ from overlap next quarter.
→ Fix: Re-check overlap once or twice a year, especially after major market moves.
When overlap is acceptable 1 min read
Overlap is not automatically bad. Sometimes you want it.
Tax-loss harvesting: investors swap between similar-but-not-identical ETFs (SPY and VOO) to lock in losses while keeping exposure.
Different account types: holding the same index in a tax-advantaged and a taxable account is normal.
Intentional overweight: if you want extra US large-cap exposure, owning two large-cap ETFs is a deliberate choice.
Fee arbitrage: sometimes a slightly different ETF from the same family has a lower fee but the same exposure. Worth checking.
What the calculator does: it makes the overlap visible. What to do about it is your call.
Worked example: SPY vs QQQ overlap 2 min read
What the calculator shows for two of the most popular ETFs
Setup: an investor holds $25,000 in SPY (S&P 500) and $25,000 in QQQ (Nasdaq 100), thinking they have diversified between “broad market” and “tech”.
The calculator shows overlap of roughly 50%. Apple, Microsoft, Nvidia, Amazon, Alphabet, Meta and Tesla are all top holdings in both ETFs. On $50,000 split between SPY (0.09% fee) and QQQ (0.20% fee), the investor pays roughly $72.50 per year. If they consolidated into just SPY, the fee would drop to $45.
The lesson: SPY and QQQ are not the diversification combo people assume. They are two different weightings of the same mega-cap tech story. Whether to hold both is a decision, but it should be a decision made with the overlap visible.
This is a fixed historical comparison, refreshed periodically. For current overlap, run the calculator live.
References
- SPY (SPDR S&P 500 ETF Trust) prospectus, State Street Global Advisors. Holdings refreshed monthly.
- QQQ (Invesco QQQ Trust) prospectus, Invesco. Tracks the Nasdaq 100 Index.
- VOO (Vanguard S&P 500 ETF) prospectus, Vanguard. Tracks the S&P 500.
- Morningstar, “Fee compounding research”. Reference for the long-term impact of expense ratios.
- SEC, “Mutual Fund and ETF Fees and Expenses”. Investor education on fund costs.
ETF terms, defined in one line
Bookmark this. Every term you will see on the calculator or in ETF research.
Exchange-Traded Fund. A basket of stocks (or bonds, commodities) that trades on an exchange like a single stock.
The percentage of holdings two ETFs share. High overlap = less real diversification from owning both.
The annual fee an ETF charges, as a percentage. 0.03% costs $3 per year per $10,000 invested.
The cumulative cost of fees over time. Compounds significantly over decades.
Spreading risk across uncorrelated assets. Overlap quietly undermines diversification.
The actual stocks an ETF owns. Listed in the fund’s prospectus, refreshed at least quarterly.
ETF Overlap Calculator: frequently asked questions
Quick answers before comparing ETFs.
Is the ETF overlap calculator free?
How many ETFs does it cover?
Does it work for international ETFs?
What overlap percentage should I worry about?
How is fee drag calculated?
Are some overlaps actually good?
How often does holdings data update?
Why do different-sounding ETFs share so much?
Deepen your understanding
This tool is one research step. These articles teach the concepts behind it.
What is an ETF?
Exchange-Traded Funds for beginners
Index ETFs vs active ETFs
What you actually pay for in each
How to read an ETF prospectus
The 5 things that matter most
Expense ratios explained
Why small fees compound into big numbers
Building a 3-ETF portfolio
The simplest diversified setup
SPY vs VOO vs IVV
Three almost identical S&P 500 ETFs compared
What is tax-loss harvesting?
Using similar-but-not-identical ETFs
Sector ETFs explained
Tech, healthcare, energy ETFs breakdown
Keep researching
Use these tools to build a cleaner ETF portfolio and compare alternatives.
Sources & methodology
Holdings data is sourced from each ETF issuer’s official filings with the SEC. Major issuers (Vanguard, BlackRock/iShares, State Street/SPDR, Invesco, Schwab) publish daily or monthly holdings updates. The calculator uses the most recently published holdings file for each ETF and refreshes monthly.
Authoritative outbound sources:
- SEC EDGAR, primary source for ETF filings and prospectuses
- State Street SPDR, SPY and major SPDR ETF holdings
- iShares (BlackRock), IVV and iShares ETF holdings
- Vanguard, VOO, VTI and other Vanguard ETF data
- SEC Investor.gov, investor education on fund fees
- Holdings pulled monthly from each ETF issuer’s official filings with the SEC.
- Overlap calculated as the sum of minimum weights for each shared stock across the two ETFs.
- Fee drag computed from the difference between expense ratios, applied to your investment amount.
- All numbers are cross-checked against the issuer’s most recent fact sheet before publishing.
Ready to compare ETF overlap?
Enter two ETF tickers to review shared holdings, overlap and fee drag before adding another fund.
Check your understanding
Answer each question, then open the explanation.
1. Can two differently named ETFs hold many of the same companies?
Show answer and why
Answer: Yes. Compare their actual holdings.
Why: A name describes the fund, not every investment it owns.
2. Why check weights and dates when interpreting overlap?
Show answer and why
Answer: They describe the exposure being compared at that time.
Why: A count of shared names does not by itself describe the size of shared exposure.
3. What should you verify before interpreting the tool’s fee comparison?
Show answer and why
Answer: The expense inputs and the assumptions used for the period.
Why: A modeled cost comparison depends on those inputs; it does not establish future returns.
AI responses are for educational purposes. Always verify with official course materials.
This lesson teaches a concept. It is general education, not advice about your money. Before you act on anything you learn here, speak to someone licensed.
AI responses are for educational purposes. Always verify with official course materials.
This lesson teaches a concept. It is general education, not advice about your money. Before you act on anything you learn here, speak to someone licensed.
This lesson teaches a concept. It is general education, not advice about your money. Before you act on anything you learn here, speak to someone licensed.
