IWF vs XLB: 0% overlap
iShares Russell 1000 Growth ETF and Materials Select Sector SPDR Fund share 0.2% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
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
IWF and XLB hold 3 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWF | in XLB | Δ |
|---|---|---|---|
| CASH | 0.1% | 0.1% | 0.0% |
| SHW | 0.1% | 4.5% | 4.4% |
| STLD | 0.0% | 4.0% | 3.9% |
Where IWF and XLB 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 | IWF | XLB | Δ |
|---|---|---|---|
| Materials | 0.3% | 99.8% | −99.6pp |
| Information Technology | 55.0% | 0.0% | +55.0pp |
| Communication Services | 15.7% | 0.0% | +15.7pp |
| Industrials | 8.5% | 0.0% | +8.5pp |
| Consumer Discretionary | 7.5% | 0.0% | +7.5pp |
| Health Care | 5.6% | 0.0% | +5.6pp |
| Financials | 4.7% | 0.0% | +4.7pp |
| Consumer Staples | 1.3% | 0.0% | +1.3pp |
Δ is IWF minus XLB, 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
99.8% of IWF by weight, held in no part of XLB.
91.4% of XLB by weight, held in no part of IWF.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IWF | XLB | |
|---|---|---|
| Top 10 holdings | 56.1% | 57.4% |
| Positions held | 370 | 28 |
| 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 IWF and XLB overlap?
IWF and XLB overlap 0.2% by portfolio weight — largely distinct portfolios. They share 3 holdings. The figure comes from current issuer holdings files (IWF as of 2026-07-23, XLB as of 2026-07-23).
How is the overlap between IWF and XLB calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IWF holds a stock at 6% and XLB 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 IWF and XLB?
That depends on your goals — we state facts, not advice. At 0.2% overlap, each fund still contributes meaningfully distinct exposure.
What does IWF own that XLB doesn't?
IWF holds 370 positions and XLB holds 28; 366 of IWF's positions don't appear in XLB at all, and they are 99.8% of IWF by weight.
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Related comparisons
Sources: issuer holdings files, IWF as of 2026-07-23, XLB as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.