What Is ETF Overlap and Why It Matters
ETF overlap measures how many of the same stocks appear in two different ETFs. If you own multiple ETFs that share the same top holdings, you're more concentrated than you think — and less diversified than your portfolio's fund count would suggest.
This is one of the most common hidden risks in portfolio construction. An investor who owns five different ETFs might assume they have broad diversification, but if those funds overlap by 60-70%, they're essentially holding variations of the same portfolio. Checking for overlap before building or adding to your portfolio is a critical step.
High-Overlap ETF Pairs You Might Own
Some of the most popular ETF combinations have surprisingly high overlap. Here are common pairs:
SPY, VOO, and IVV — Nearly 100% overlap. All three track the S&P 500 index. Owning more than one is pointless. See our SPY vs VOO comparison.
VTI and VOO — Roughly 85% overlap. VTI includes all of VOO's holdings plus mid-cap and small-cap stocks. The S&P 500 represents about 80% of VTI by weight, so the incremental diversification from owning both is minimal.
QQQ and VGT — Significant overlap in mega-cap tech stocks. Both hold Apple, Microsoft, and Nvidia as top positions, though QQQ tracks the Nasdaq-100 (which includes non-tech stocks) while VGT focuses purely on the technology sector.
VOO and SCHD — Moderate overlap. Both hold large US stocks, but SCHD filters for dividend quality and screens out many of the largest tech stocks. This pair provides more diversification than VTI + VOO but still shares many holdings.
How to Check ETF Overlap
The easiest method is to use the ETF Beacon comparison tool. Enter any two ETF tickers to see their shared holdings, unique holdings, and overall overlap percentage. This gives you an instant picture of whether two funds provide genuinely different exposure.
Step 1: Navigate to the comparison tool and enter your two ETF tickers.
Step 2: Review the overlap percentage. Under 20% means low overlap (good diversification). Between 20-50% is moderate. Above 50% means you should question whether you need both funds.
Step 3: Look at the shared top holdings. If the same stocks dominate both funds, your portfolio's performance will be highly correlated regardless of the headline overlap number.
Step 4: Check the sector overlap. Two funds might hold different stocks but still be concentrated in the same sectors, which creates similar risk exposures.
How Much Overlap Is Too Much?
There's no universal rule, but here are practical guidelines for managing overlap between ETFs in your portfolio:
Under 20% overlap: Excellent. These funds provide genuinely different exposure. A US stock ETF paired with an international ETF typically falls in this range.
20-40% overlap: Acceptable. The funds share some holdings but serve different purposes. A total market ETF paired with a small-cap or value ETF fits here.
40-70% overlap: Questionable. Ask yourself what the second fund adds that the first doesn't already provide. You may be adding complexity without meaningful diversification.
Over 70% overlap: Consolidate. You're paying two expense ratios for essentially the same exposure. Pick the cheaper fund and simplify.
Building a Low-Overlap Portfolio
True diversification requires combining ETFs that cover different parts of the investment universe. Here's how to build a portfolio with minimal overlap:
Diversify across asset classes. Stocks and bonds have near-zero overlap. Adding a bond ETF like BND to a stock portfolio is guaranteed diversification. Learn more in our portfolio building guide.
Diversify across geographies. A US stock ETF and an international ETF like VXUS have very low overlap since they hold stocks from different countries.
Diversify across market caps. Large-cap and small-cap ETFs hold different companies by definition. Pairing VOO (large-cap) with a small-cap ETF gives you broader exposure than owning multiple large-cap funds.
Avoid stacking similar strategies. Owning a total market ETF, an S&P 500 ETF, and a large-cap growth ETF gives you triple exposure to the same mega-cap stocks. Pick one approach and supplement with something different.
When Some Overlap Is Acceptable
Not all overlap is bad. A core-satellite strategy intentionally uses a broad core fund plus targeted satellite positions that overlap with the core. For example, holding VTI as your core and adding a semiconductor ETF as a satellite means you're doubling down on semiconductor stocks — but that's the point.
The key distinction is between intentional and accidental overlap. If you've deliberately chosen to overweight a sector, overlap is a feature. If you didn't realize your three equity ETFs all hold the same top 10 stocks, overlap is a problem.
Check Your Existing Portfolio Now
If you own more than one equity ETF, take five minutes to check your overlap today. Go to the ETF Beacon comparison tool, enter your funds pairwise, and see where you stand.
Common findings that surprise investors: owning both a total market fund and an S&P 500 fund (85% overlap), holding multiple thematic tech funds that all own the same mega-cap stocks, or pairing dividend funds that share most of their large-cap holdings.
Simplifying your portfolio by eliminating redundant positions can reduce fees, simplify rebalancing, and actually improve diversification. Sometimes less is more.
