ARKG vs IBB overlap - what they share and where they differ
ARKG and IBB share 9.6% of their weight across 22 common positions, read from what each fund reported to the SEC.
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.
ARKG and IBB
9.6%
22 shared positions
ARKG
ARK Genomic Revolution ETF
Reported positions cover 100% of the fund, 32 positions · Jul 31, 2026
Top 10: 59.1%·Holdings of ARKG
IBB
iShares Biotechnology ETF
Reported positions cover 100% of the fund, 238 positions · Jun 30, 2026
Top 10: 44.7%·Holdings of IBB
Reported positions cover ARKG 100%, IBB 100% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
IBB vs ARKG side by side
ARKGARK Genomic Revolution ETF
32
stock positions reported to the SEC
20.6% of its weight is in 10 names IBB does not hold
IBBiShares Biotechnology ETF
238
stock positions reported to the SEC
90.3% of its weight is in 216 names ARKG does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Healthcare: IBB has 8.3 points more of it.
The figures side by side
| ARKG | IBB | |
|---|---|---|
| Filing date | Jul 31, 2026 | Jun 30, 2026 |
| Stock positions reported | 32 | 238 |
| Weight of the ten largest | 59.1% | 44.7% |
| Largest position | TXG 9.4% | VRTX 8.1% |
| Held alone | 10 positions, 20.6% | 216 positions, 90.3% |
| Covered by stock positions | 100% | 100% |
Holdings they share
| Stock | In ARKG | In IBB | Counted |
|---|---|---|---|
| NTRANATERA INC | 4.13% | 2.89% | 2.89% |
| ILMNILLUMINA INC | 4.74% | 2.07% | 2.07% |
| IONSIONIS PHARMACEUTICALS INC | 1.77% | 1.00% | 1.00% |
| TEMTEMPUS AI INC | 6.56% | 0.48% | 0.48% |
| TWSTTWIST BIOSCIENCE CORP | 7.73% | 0.48% | 0.48% |
| CRSPCRISPR THERAPEUTICS AG | 6.29% | 0.38% | 0.38% |
| VCYTVERACYTE INC | 2.55% | 0.36% | 0.36% |
| TXG10X GENOMICS INC | 9.39% | 0.34% | 0.34% |
| ADPTADAPTIVE BIOTECHNOLOGIES CORP | 2.57% | 0.26% | 0.26% |
| BEAMBEAM THERAPEUTICS INC | 3.78% | 0.25% | 0.25% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in ARKG
Only in IBB
Questions people ask
Is ARKG the same as IBB?
9.6% of their weight sits in the same 22 holdings. ARKG also reports GH, LLY, BFLY, which the other does not. IBB also reports VRTX, AMGN, GILD, which the other does not.
How is the overlap between ARKG and IBB measured?
For every stock both funds report, the smaller of the two weights counts, and the sum is the overlap. The reported positions cover 100% of ARKG and 100% of IBB, so the number cannot exceed the smaller coverage.
Which holds more, IBB or ARKG?
ARKG reports 32 stock positions and IBB reports 238. 20.6% of ARKG's weight sits in names IBB does not hold, and 90.3% of IBB's weight in names ARKG does not hold. The ten largest positions are 59.1% of ARKG and 44.7% of IBB.
How do ARKG and IBB differ by sector?
The widest gap is Healthcare: IBB has 8.3 points more of it. Sectors come from each holding's SIC code in its SEC record, summed by the weight the fund reports.
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.
Add a third fund in the tool·All fund pairs
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.