DIA vs IWM: how much do they really overlap?
DIA (SPDR Dow Jones Industrial Average ETF, tracking the Dow Jones Industrial Average) and IWM (iShares Russell 2000 ETF, tracking the Russell 2000) overlap by roughly 0% by weight. 0 of DIA's top 10 holdings also appear in IWM. A 50/50 blend of the two behaves like about 77 equally-weighted bets (diversification grade A). In short, the two funds hold almost none of the same securities — they are complementary, not redundant.
The same companies, in both funds
These 0 holdings appear in both DIA and IWM. The weight columns show how much of each fund each name represents.
| Holding | in DIA | in IWM |
|---|
Only in DIA
SPDR Dow Jones Industrial Average ETF — US blue-chip (Dow 30). Its biggest holdings that IWM doesn’t have:
| CAT Caterpillar Inc. | 11.76% |
| GS The Goldman Sachs Group, Inc. | 11.61% |
| UNH UnitedHealth Group Incorporated | 4.78% |
| MSFT Microsoft Corporation | 4.20% |
| AMGN Amgen Inc. | 4.10% |
| GOOGL Alphabet Inc. | 4.03% |
| HD The Home Depot, Inc. | 3.99% |
| SHW The Sherwin-Williams Company | 3.92% |
Only in IWM
iShares Russell 2000 ETF — US small-cap. Its biggest holdings that DIA doesn’t have:
| MOGA MOOG INC CLASS A | 0.38% |
| HUT HUT CORP | 0.37% |
| VSAT VIASAT INC | 0.35% |
| BTSG BRIGHTSPRING HEALTH SERVICES INC | 0.35% |
| CYTK CYTOKINETICS INC | 0.35% |
| MXL MAXLINEAR INC | 0.34% |
| AGX ARGAN INC | 0.34% |
| UMBF UMB FINANCIAL CORP | 0.33% |
So — essentially different. Should you hold both?
DIA and IWM hold almost none of the same securities — they are complementary, not redundant. Held together they genuinely broaden your exposure — a 50/50 blend reaches ~77 effective positions (grade A), because they hold largely different securities.
Holdings as of — DIA: Jun 29, 2026 (State Street Global Advisors); IWM: Jun 30, 2026 (iShares (BlackRock)). Refreshed monthly. Overlap is measured across each fund’s largest holdings (top 50); the diffuse long tail barely moves the math.
See this for YOUR whole portfolio, free →DIA vs IWM — FAQ
- How much do DIA and IWM overlap?
- DIA and IWM overlap by approximately 0% measured by portfolio weight — that is the share of the smaller fund's holdings (by weight) that also sit inside the other. 0 of DIA's 10 largest holdings are also held by IWM. They share 0 of their listed top holdings in total.
- Is it redundant to hold both DIA and IWM?
- Because they hold almost none of the same securities — they are complementary, not redundant, holding both is not redundant — each fund covers largely different holdings, so together they broaden your exposure. A 50/50 blend has an effective 77 positions and a A diversification grade.
- What does IWM hold that DIA doesn't?
- IWM's largest holdings that DIA doesn't hold include MOGA, HUT, VSAT, BTSG, CYTK. Its category is US small-cap, versus DIA's US blue-chip (Dow 30).
- Which is more concentrated, DIA or IWM?
- DIA's top 10 holdings are 59% of its listed weight; IWM's are 26%. The more concentrated fund leans harder on its largest names.