IWD vs SPYM: 59% overlap
iShares Russell 1000 Value ETF and State Street SPDR Portfolio S&P 500 ETF share 58.8% 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 1.4. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IWD and SPYM hold 425 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWD | in SPYM | Δ |
|---|---|---|---|
| AAPL | 5.9% | 7.4% | 1.5% |
| MSFT | 3.9% | 4.4% | 0.5% |
| AMZN | 5.7% | 3.6% | 2.2% |
| JPM | 2.6% | 1.5% | 1.1% |
| BRK-B | 2.5% | 1.4% | 1.1% |
| XOM | 1.8% | 1.0% | 0.8% |
| JNJ | 1.7% | 1.0% | 0.7% |
| WMT | 1.2% | 0.7% | 0.5% |
| INTC | 1.2% | 0.7% | 0.5% |
| ABBV | 1.2% | 0.7% | 0.4% |
Where IWD and SPYM 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 | IWD | SPYM | Δ |
|---|---|---|---|
| Information Technology | 18.0% | 37.5% | −19.5pp |
| Financials | 19.6% | 12.4% | +7.2pp |
| Communication Services | 3.3% | 9.3% | −6.0pp |
| Health Care | 12.7% | 9.1% | +3.6pp |
| Consumer Staples | 7.4% | 4.6% | +2.8pp |
| Energy | 6.1% | 3.4% | +2.7pp |
| Industrials | 11.3% | 8.9% | +2.4pp |
| Materials | 3.7% | 1.8% | +1.9pp |
Δ is IWD minus SPYM, 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
9.5% of IWD by weight, held in no part of SPYM.
36.0% of SPYM by weight, held in no part of IWD.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IWD | SPYM | |
|---|---|---|
| Top 10 holdings | 27.8% | 36.9% |
| Positions held | 872 | 507 |
| Cost per $10,000 held, per year | $19 | $2 |
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 IWD and SPYM overlap?
IWD and SPYM overlap 58.8% by portfolio weight — substantial duplication if you hold both. They share 425 holdings. The figure comes from current issuer holdings files (IWD as of 2026-07-23, SPYM as of 2026-07-23).
How is the overlap between IWD and SPYM calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IWD holds a stock at 6% and SPYM 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 IWD and SPYM?
That depends on your goals — we state facts, not advice. At 58.8% overlap, each fund still contributes meaningfully distinct exposure.
What does IWD own that SPYM doesn't?
IWD holds 872 positions and SPYM holds 507; 446 of IWD's positions don't appear in SPYM at all, and they are 9.5% of IWD by weight.
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Related comparisons
Sources: issuer holdings files, IWD as of 2026-07-23, SPYM as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.