IWM vs IWO overlap - what they share and where they differ
IWM and IWO share 56.6% of their weight across 932 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.
IWM and IWO
56.6%
932 shared positions
IWM
iShares Russell 2000 ETF
Reported positions cover 100% of the fund, 1,785 positions · Jun 30, 2026
Top 10: 3.4%·Holdings of IWM
IWO
iShares Russell 2000 Growth ETF
Reported positions cover 99% of the fund, 975 positions · Jun 30, 2026
Top 10: 6.1%·Holdings of IWO
Reported positions cover IWM 100%, IWO 99% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
IWO vs IWM side by side
IWMiShares Russell 2000 ETF
1,785
stock positions reported to the SEC
35.1% of its weight is in 853 names IWO does not hold
IWOiShares Russell 2000 Growth ETF
975
stock positions reported to the SEC
0.4% of its weight is in 43 names IWM does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Financial Services: IWM has 16.0 points more of it.
The figures side by side
| IWM | IWO | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 1,785 | 975 |
| Weight of the ten largest | 3.4% | 6.1% |
| Largest position | MOG.A 0.4% | MOG.A 0.7% |
| Held alone | 853 positions, 35.1% | 43 positions, 0.4% |
| Covered by stock positions | 100% | 99% |
Holdings they share
| Stock | In IWM | In IWO | Counted |
|---|---|---|---|
| MOG.AMoog, Inc. | 0.38% | 0.73% | 0.38% |
| HUTHut 8 Corp. | 0.37% | 0.38% | 0.37% |
| BTSGBrightSpring Health Services, Inc. | 0.35% | 0.68% | 0.35% |
| AGXArgan, Inc. | 0.34% | 0.66% | 0.34% |
| MXLMaxLinear, Inc. | 0.34% | 0.66% | 0.34% |
| COMPCompass Diversified Holdings | 0.32% | 0.53% | 0.32% |
| FROGJFrog Ltd. | 0.31% | 0.59% | 0.31% |
| KRYSKrystal Biotech, Inc. | 0.30% | 0.58% | 0.30% |
| RIOTRiot Platforms, Inc. | 0.30% | 0.39% | 0.30% |
| ESEESCO Technologies, Inc. | 0.29% | 0.56% | 0.29% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in IWM
Only in IWO
Questions people ask
Is IWM the same as IWO?
56.6% of their weight sits in the same 932 holdings. IWM also reports VSAT, CTRE, TEX, which the other does not. IWO also reports AGEN, AP, BRCB, which the other does not.
How is the overlap between IWM and IWO 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 IWM and 99% of IWO, so the number cannot exceed the smaller coverage.
Which holds more, IWO or IWM?
IWM reports 1,785 stock positions and IWO reports 975. 35.1% of IWM's weight sits in names IWO does not hold, and 0.4% of IWO's weight in names IWM does not hold. The ten largest positions are 3.4% of IWM and 6.1% of IWO.
How do IWM and IWO differ by sector?
The widest gap is Financial Services: IWM has 16.0 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.