IOO vs VOO: Holdings Overlap
iShares · 110 holdings · $9.3B · as of 2026-03-31
Vanguard · 504 holdings · $1.03T · as of 2026-03-31
How similar are IOO and VOO?
iShares Global 100 ETF (IOO, by iShares) holds 110 positions; Vanguard 500 Index Fund (VOO, by Vanguard) holds 504. They have 51 holdings in common, and by portfolio weight the two funds are 49.2% identical. In practical terms the pair is moderately overlapping; they share a meaningful core, but each fund adds distinct exposure.
- Overlap by Weight
- 49.2%Sum of the smaller weight of each shared holding
- Shared Holdings
- 51IOO holds 110 · VOO holds 504
- Weight in Shared Holdings
- IOO 79%·VOO 49%Share of each fund's weight in stocks both funds own
Based on each fund's latest official holdings. How is this calculated?
What makes each fund different
Only in IOO
59 of 110 positions (20.8% of the fund) are not held by VOO. Showing the top 30 by weight.
Sector Breakdown
| Sector | IOO | VOO |
|---|---|---|
| Information Technology | 42.3% | 32.7% |
| Financials | 10.0% | 12.4% |
| Communication Services | 10.1% | 10.5% |
| Consumer Discretionary | 8.5% | 9.9% |
| Health Care | 9.8% | 9.5% |
| Other Sectors | 19.0% | 24.9% |
Share of each fund's portfolio weight by GICS-style sector, compiled from issuer fund data and our own classification of the holdings, not the issuers' published sector charts.
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| IOO | +5.6% | +16.0% | +31.2% | +25.4% | +16.4% | +16.6% | 0.80% |
| VOO | +3.4% | +14.0% | +23.7% | +21.3% | +13.4% | +15.4% | 1.03% |
Total returns including dividends, from adjusted daily closes as of 2026-08-07. 3Y/5Y/10Y are annualized. Yield is trailing-12-month distributions over the last close. Past performance does not predict future results.
Project the growth of $10,000 in IOO vs VOO →
Shared Holdings(51)
The top 10 shared positions account for 71% of the overlap, led by NVDA, AAPL and MSFT.
 NVDANVIDIA Corp. COM | 12.13% | 7.58% | 7.58% |
|---|---|---|---|
 AAPLApple Inc. COM | 10.66% | 6.66% | 6.66% |
 MSFTMicrosoft Corp. COM | 7.87% | 4.91% | 4.91% |
 AMZNAmazon.com, Inc. COM | 5.82% | 3.64% | 3.64% |
 GOOGLAlphabet Inc. CAP STK CL A | 4.79% | 2.99% | 2.99% |
 AVGOBroadcom Inc COM | 4.20% | 2.62% | 2.62% |
 GOOGAlphabet Inc. CAP STK CL C | 3.84% | 2.40% | 2.40% |
 JPMJPMorgan Chase & Co. COM | 2.27% | 1.34% | 1.34% |
 LLYEli Lilly & Co. COM | 2.09% | 1.30% | 1.30% |
 XOMExxon Mobil Corp. COM | 2.03% | 1.27% | 1.27% |
 JNJJohnson & Johnson COM | 1.69% | 1.05% | 1.05% |
 WMTWalmart Inc COM | 1.56% | 0.97% | 0.97% |
 MAMasterCard Incorporated CL A | 1.16% | 0.73% | 0.73% |
 CVXChevron Corp. COM | 1.11% | 0.69% | 0.69% |
 PGThe Procter & Gamble Co. COM | 0.96% | 0.60% | 0.60% |
 CATCaterpillar Inc COM | 0.95% | 0.59% | 0.59% |
 CSCOCisco Systems, Inc. COM | 0.87% | 0.55% | 0.55% |
 MRKMerck & Co., Inc COM | 0.86% | 0.53% | 0.53% |
 GEGeneral Electric Co. | 0.85% | 0.53% | 0.53% |
 KOCoca-Cola Co (The) COM | 0.84% | 0.53% | 0.53% |
 RTXRTX Corp. COM | 0.74% | 0.46% | 0.46% |
 PMPhilip Morris International Inc. COM | 0.74% | 0.46% | 0.46% |
 GSGoldman Sachs Group, Inc. (The) | 0.73% | 0.43% | 0.43% |
 LINLinde PLC COM EUR0.001 | 0.66% | 0.41% | 0.41% |
 IBMInternational Business Machines Corp. COM | 0.65% | 0.41% | 0.41% |
Frequently Asked Questions
How much do IOO and VOO overlap?
IOO and VOO overlap by 49.2% of portfolio weight. They share 51 holdings (IOO holds 110 positions and VOO holds 504), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IOO and VOO?
The two portfolios are 49.2% identical by weight. Owning both is defensible: they share a meaningful core, but each fund adds exposure the other lacks.
What are the biggest shared holdings of IOO and VOO?
The largest positions held by both funds are NVDA, AAPL, MSFT, AMZN and GOOGL. Together the top 10 shared positions account for 71% of the total overlap.
What does IOO own that VOO doesn't?
59 positions (20.8% of IOO) are unique to IOO, led by 005930, ASML and 700. In the other direction, 453 positions (50.6% of VOO) are unique to VOO.