ETF overlap tool - which funds hold the same stocks

How much of one fund is already inside another, measured from their SEC filings.

Each week Ploutos reads the reported positions of the largest US equity ETFs and measures, pair by pair, the weight they share: for every stock both funds hold, the smaller of the two weights counts. Two funds tracking the same index land near 100%. A sector fund inside a broad index fund lands at roughly that sector's weight.

268 funds, every equity position each reports to the SEC, filings dated Mar 31, 2026 to Jun 30, 2026. Coverage is the share of each fund those positions add up to, so a fund holding futures or cash shows less than 100, and both coverages are shown with every pair.

ETF overlap calculator: compare two to five funds

Pick the funds you hold or are looking at. The overlap is read from the positions each one reported to the SEC, so it is the same number the table below uses.

ARKGARK Genomic Revolution ETF
XBIState Street(R) SPDR(R) S&P(R) Biotech ETF

Up to 5 funds at a time.

ARKG and XBI

9.8%

12 shared positions

Reported positions cover ARKG 100%, XBI 100% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.

Open ARKG vs XBI as its own page

Holdings they share

StockIn ARKGIn XBICounted
TWSTTWIST BIOSCIENCE CORP8.99%1.41%1.41%
NTRANATERA INC4.07%1.16%1.16%
BEAMBEAM THERAPEUTICS INC5.43%1.08%1.08%
CRSPCRISPR THERAPEUTICS AG8.91%1.02%1.02%
IONSIONIS PHARMACEUTICALS INC1.74%1.00%1.00%
NTLAINTELLIA THERAPEUTICS INC3.82%0.91%0.91%
VCYTVERACYTE INC2.66%0.82%0.82%
RXRXRECURSION PHARMACEUTICALS INC3.51%0.76%0.76%
ABSIABSCI CORP4.78%0.56%0.56%
NRIXNURIX THERAPEUTICS INC2.33%0.56%0.56%

Only in ARKG

TEMTEMPUS AI INC9.42%
TXG10X GENOMICS INC5.77%
ILMNILLUMINA INC4.03%
PSNLPERSONALIS INC3.58%
GHGUARDANT HEALTH INC3.49%
COMPASS PATHWAYS PLC2.43%
ADPTADAPTIVE BIOTECHNOLOGIES CORP2.42%
WGSGENEDX HOLDINGS CORP2.04%
SDGRSCHRODINGER INC2.03%
ARCTARCTURUS THERAPEUTICS HOLDINGS INC1.96%

Only in XBI

APGEApogee Therapeutics Inc1.49%
MRNAModerna Inc1.41%
ORKAOruka Therapeutics Inc1.38%
KYMRKymera Therapeutics Inc1.36%
VKTXViking Therapeutics Inc1.30%
PRAXPraxis Precision Medicines Inc1.29%
ERASErasca Inc1.27%
CGONCG oncology Inc1.20%
RVMDRevolution Medicines Inc1.20%
RYTMRhythm Pharmaceuticals Inc1.20%

Fund pairs with the most shared weight

Sorted by how much of one fund is inside the other. Same index funds sit at the top by construction.

FundFundOverlapSharedCoverage
SPYVOOVANGUARD 500 INDEX FUND99.8%498100% / 100%
IJHiShares Core S&P Mid-Cap ETFMDYState Street SPDR S&P MidCap 400SM ETF Trust99.5%400100% / 99%
IJHiShares Core S&P Mid-Cap ETFSPMDState Street(R) SPDR(R) Portfolio S&P 400(TM) Mid Cap ETF97.6%391100% / 100%
MDYState Street SPDR S&P MidCap 400SM ETF TrustSPMDState Street(R) SPDR(R) Portfolio S&P 400(TM) Mid Cap ETF97.4%39199% / 100%
IVWiShares S&P 500 Growth ETFSPYGState Street(R) SPDR(R) Portfolio S&P 500(R) Growth ETF97.4%142100% / 100%
SPYVVVANGUARD LARGE-CAP INDEX FUND96.3%394100% / 100%
VOOVANGUARD 500 INDEX FUNDVVVANGUARD LARGE-CAP INDEX FUND96.2%395100% / 100%
FENYFidelity MSCI Energy Index ETFVDEVANGUARD ENERGY INDEX FUND95.7%92100% / 100%
IVViShares Core S&P 500 ETFSPY95.5%478100% / 100%
IVViShares Core S&P 500 ETFVOOVANGUARD 500 INDEX FUND95.3%477100% / 100%

Stocks held by the most funds

Which companies appear across the most funds in the set, and at what average weight where they appear.

StockFundsAvg weight
ORCLOracle Corp910.6%
KOCoca-Cola Co/The900.7%
NVDANVIDIA Corp827.2%
AVGOBroadcom Inc793.7%
MRKMerck & Co Inc781.0%
NTRSNorthern Trust Corp770.3%
MSFTMicrosoft Corp754.6%
AAPLApple Inc736.2%
INTCIntel Corp731.8%
KLACKLA Corp731.2%

Questions people ask

What is ETF overlap?

The share of two funds that is invested in the same companies, weighted by how much each fund holds of them. Two funds with different names can hold mostly the same stocks, so owning both adds less variety than the two names suggest.

How much ETF overlap is too much?

There is no single threshold. Two funds tracking the same index overlap almost completely by design, and a sector fund inside a broad index fund overlaps by roughly that sector's weight. What the number does is replace a guess with a measurement, so the composition of a portfolio is known rather than assumed.

Where do the numbers come from?

From each fund's own N-PORT filing to the SEC, which lists every position and its weight. The comparison uses every equity position the fund reports; cash, futures and bonds are not counted, which is why a coverage figure sits next to every result. Holdings change between filings.

How is this ETF overlap comparison different from other overlap tools?

It reads the positions each fund reported to the SEC in its latest N-PORT filing, not a vendor feed, and shows each fund's coverage next to every number so you can see how much of the fund the comparison actually saw. It covers US-listed equity ETFs only: UCITS funds do not file N-PORT, so they are not in the set.

Funds in this week's set

One page per fund with its reported positions, sector split and the funds most like it.

For what the number does and does not tell you, and how to check two funds of your own: read the ETF overlap guide

Descriptive data from public SEC filings. Nothing on this page is a recommendation to buy, sell or hold any fund or stock, and holdings change between filings.