IWM vs VWO: how much do they really overlap?
IWM (iShares Russell 2000 ETF, tracking the Russell 2000) and VWO (Vanguard FTSE Emerging Markets ETF, tracking the FTSE Emerging Markets All Cap) overlap by roughly 0% by weight. 0 of IWM's top 10 holdings also appear in VWO. A 50/50 blend of the two behaves like about 165 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 IWM and VWO. The weight columns show how much of each fund each name represents.
| Holding | in IWM | in VWO |
|---|
Only in IWM
iShares Russell 2000 ETF — US small-cap. Its biggest holdings that VWO 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% |
Only in VWO
Vanguard FTSE Emerging Markets ETF — emerging markets. Its biggest holdings that IWM doesn’t have:
| 2330 Taiwan Semiconductor Manufacturing Co. Ltd. | 14.64% |
| 700 Tencent Holdings Ltd. | 2.74% |
| 9988 Alibaba Group Holding Ltd. | 2.26% |
| 2454 MediaTek Inc. | 1.62% |
| 2308 Delta Electronics Inc. | 1.20% |
| 2317 Hon Hai Precision Industry Co. Ltd. | 0.90% |
| RELIANCE Reliance Industries Ltd. | 0.77% |
| 939 China Construction Bank Corp. Class H | 0.77% |
So — essentially different. Should you hold both?
IWM and VWO hold almost none of the same securities — they are complementary, not redundant. Held together they genuinely broaden your exposure — a 50/50 blend reaches ~165 effective positions (grade A), because they hold largely different securities.
Holdings as of — IWM: Jun 30, 2026 (iShares (BlackRock)); VWO: May 31, 2026 (Vanguard). 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 →IWM vs VWO — FAQ
- How much do IWM and VWO overlap?
- IWM and VWO 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 IWM's 10 largest holdings are also held by VWO. They share 0 of their listed top holdings in total.
- Is it redundant to hold both IWM and VWO?
- 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 165 positions and a A diversification grade.
- What does VWO hold that IWM doesn't?
- VWO's largest holdings that IWM doesn't hold include 2330, 700, 9988, 2454, 2308. Its category is emerging markets, versus IWM's US small-cap.
- Which is more concentrated, IWM or VWO?
- IWM's top 10 holdings are 26% of its listed weight; VWO's are 66%. The more concentrated fund leans harder on its largest names.