IWM vs VTWNX: 1% overlap
iShares Russell 2000 ETF and Vanguard Target Retirement 2020 share 1.4% 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 — VTWNX as of 2026-03-31, the rest through 2026-07-23. 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 2.0. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IWM and VTWNX hold 1,839 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWM | in VTWNX | Δ |
|---|---|---|---|
| CASH | 0.2% | 1.7% | 1.5% |
| MC | 0.1% | 0.0% | 0.1% |
| ENR | 0.0% | 0.0% | 0.0% |
| AIR | 0.2% | 0.0% | 0.1% |
| KTB | 0.1% | 0.0% | 0.1% |
| CNR | 0.1% | 0.0% | 0.1% |
| ORA | 0.2% | 0.0% | 0.2% |
| CCO | 0.0% | 0.0% | 0.0% |
| UCB | 0.1% | 0.0% | 0.1% |
| AI | 0.0% | 0.0% | 0.0% |
Where IWM and VTWNX 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 | VTWNX | Δ |
|---|---|---|---|
| Unclassified | 0.0% | 29.8% | −29.8pp |
| Health Care | 19.9% | 2.7% | +17.2pp |
| Treasuries | 0.0% | 17.1% | −17.1pp |
| Financials | 19.0% | 8.2% | +10.8pp |
| Industrials | 14.7% | 4.0% | +10.7pp |
| MBS Pass-Through | 0.0% | 7.2% | −7.2pp |
| Consumer Discretionary | 9.4% | 2.9% | +6.5pp |
| Corporate — industrial & other | 0.0% | 5.5% | −5.5pp |
Δ is IWM minus VTWNX, 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
4.2% of IWM by weight, held in no part of VTWNX.
96.9% of VTWNX 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 | VTWNX | |
|---|---|---|
| Top 10 holdings | 3.3% | 44.9% |
| Positions held | 1,967 | 7 |
| Cost per $10,000 held, per year | $19 | $8 |
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 VTWNX overlap?
IWM and VTWNX overlap 1.4% by portfolio weight — largely distinct portfolios. They share 1,839 holdings. The figure comes from current issuer holdings files (IWM as of 2026-07-23, VTWNX as of 2026-03-31).
How is the overlap between IWM and VTWNX 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 VTWNX 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 VTWNX?
That depends on your goals — we state facts, not advice. At 1.4% overlap, each fund still contributes meaningfully distinct exposure.
What does IWM own that VTWNX doesn't?
IWM holds 1,967 positions and VTWNX holds 7; 127 of IWM's positions don't appear in VTWNX at all, and they are 4.2% of IWM by weight.
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Related comparisons
Sources: issuer holdings files, IWM as of 2026-07-23, VTWNX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.