IWM vs VFMO: 21% overlap
iShares Russell 2000 ETF and Vanguard U.S. Momentum Factor ETF share 21.4% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 4 months apart — VFMO as of 2026-03-31, the rest through 2026-07-27. Each fund is compared using its most recent file, so any trading in between shows up as a difference.
You would hold two tickers and get the diversification of 1.8. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IWM and VFMO hold 402 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWM | in VFMO | Δ |
|---|---|---|---|
| KRYS | 0.3% | 0.2% | 0.1% |
| CYTK | 0.3% | 0.2% | 0.1% |
| FCFS | 0.3% | 0.2% | 0.1% |
| SSRM | 0.2% | 0.2% | 0.0% |
| ZWS | 0.2% | 0.2% | 0.1% |
| LUMN | 0.2% | 0.2% | 0.0% |
| PTCT | 0.2% | 0.2% | 0.0% |
| IDCC | 0.2% | 0.2% | 0.0% |
| LQDA | 0.2% | 0.2% | 0.0% |
| AGX | 0.2% | 0.2% | 0.1% |
Where IWM and VFMO differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | IWM | VFMO | Δ |
|---|---|---|---|
| Financials | 19.2% | 6.3% | +12.9pp |
| Industrials | 14.6% | 24.4% | −9.9pp |
| Real Estate | 6.0% | 0.1% | +5.9pp |
| Information Technology | 12.6% | 17.0% | −4.4pp |
| Utilities | 3.0% | 0.0% | +3.0pp |
| Health Care | 19.8% | 22.3% | −2.5pp |
| Materials | 4.2% | 6.2% | −2.0pp |
| Energy | 5.8% | 7.7% | −1.9pp |
Δ is IWM minus VFMO, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
67.5% of IWM by weight, held in no part of VFMO.
64.5% of VFMO by weight, held in no part of IWM.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IWM | VFMO | |
|---|---|---|
| Top 10 holdings | 3.3% | 10.2% |
| Positions held | 1,965 | 672 |
| Cost per $10,000 held, per year | $19 | $13 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do IWM and VFMO overlap?
IWM and VFMO overlap 21.4% by portfolio weight — moderate overlap. They share 402 holdings. The figure comes from current issuer holdings files (IWM as of 2026-07-27, VFMO as of 2026-03-31).
How is the overlap between IWM and VFMO calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IWM holds a stock at 6% and VFMO holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both IWM and VFMO?
That depends on your goals — we state facts, not advice. At 21.4% overlap, each fund still contributes meaningfully distinct exposure.
What does IWM own that VFMO doesn't?
IWM holds 1,965 positions and VFMO holds 672; 1,562 of IWM's positions don't appear in VFMO at all, and they are 67.5% of IWM by weight.
You probably hold more than two funds
This page compares IWM and VFMO. Paste your whole portfolio — brokerage, 401(k), IRA — and see the overlap across every fund at once, plus what you actually own underneath them and your own Effective Funds number. Free, no account, nothing stored.
X-ray my portfolio — free →Watch IWM vs VFMO
We re-read both funds’ published holdings every weeknight. Leave an address and we'll tell you when what's inside actually changes.
Not sending yet — email alerts are built but switched off, and you'll be among the first when they turn on. No spam, one-click unsubscribe.
Related comparisons
Sources: issuer holdings files, IWM as of 2026-07-27, VFMO as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.