IOO vs VOO: Differences, Returns & Fees
IOO and VOO hold 50% of their weight in the same names, and IOO returned +21.1% over the year. Net assets: $9.4bn on Oct 9, 2026 for iShares Global 100 ETF, and $1.0tn on Sep 30, 2026 for Vanguard S&P 500 ETF.
VOO costs 0.37 points a year less; their one-year returns differ by 3.8 points; VOO is far larger, $1.0tn against $9.2bn.
| IOO | VOO | |
|---|---|---|
| Expense ratio | 0.40% | 0.03% |
| Net assets, as of Sep 30, 2026 | $9.2bn | $1.0tn |
| Total return, 1 year | +21.1% | +17.3% |
| What it tracks | S&P Global 100 | S&P 500 Index |
| Holdings in common | 50% | |
| Top ten holdings, share of the fund | 59.9% | 37.8% |
Holdings in common uses holdings dated Aug 31, 2026 and Oct 9, 2026.
What they hold in common
By the books each fund has filed, IOO and VOO hold 50% of their money in the same securities at the same weight. Above 50%, holding both is close to holding one of them twice. Holdings dated Aug 31, 2026 and Oct 9, 2026.
half
50% in common
On the same fields
IOO and VOO on the fields both publish, as of Oct 9, 2026. Source: ETFIQ.
About IOO
IOO tracks an index. Over the year to Oct 9, 2026 it returned +21.1% with distributions reinvested. The prospectus expense ratio is 0.40% a year. By its holdings published by its issuer for Oct 9, 2026, 79% of the fund by weight is stocks the S&P 500 also holds, across 104 positions, with the top ten at 59.9%.
About VOO
VOO tracks the S&P 500. Over the year to Oct 9, 2026 it returned +17.3% with distributions reinvested, against +17.3% for its benchmark, the S&P 500 Index. The prospectus expense ratio is 0.03% a year. By its holdings published by its issuer as of Aug 31, 2026, 100% of the fund by weight is stocks the S&P 500 also holds, across 507 positions, with the top ten at 37.8%.
Questions people ask
- Which returned more over the last year, IOO or VOO?
- In the year to Oct 9, 2026, with distributions reinvested, IOO returned +21.1% and VOO +17.3%.
- Which is cheaper, IOO or VOO?
- VOO is cheaper, by 0.37 percentage points a year. That is about $37 on $10,000 held for a year. Fees come from each fund's prospectus.
ETFIQ links to the documents behind every figure; a link is not an endorsement. A comparison is not a recommendation.
How this is computed
Overlap adds up the smaller of the two weights for each security both funds hold.
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ETFIQ, IOO against VOO, data as of Oct 9, 2026. https://etfiq.com/compare/any/ioo-vs-voo
ETFIQ. (Oct 9, 2026). IOO against VOO. Retrieved from https://etfiq.com/compare/any/ioo-vs-voo
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