Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
IVV vs VO: how they differ
IVV and VO hold 15% of their weight in the same names, and IVV returned more over the year.
iShares Core S&P 500 ETF and Vanguard Mid-Cap Index Fund.
What they hold in common
By the books each fund has filed, IVV and VO hold 15% of their money in the same securities at the same weight.
| Holding | IVV | VO |
|---|---|---|
| Western Digital Corp. | 0.34% | 1.07% |
| Vertiv Holdings Co. | 0.20% | 1.23% |
| Quanta Services, Inc. | 0.17% | 1.05% |
| Howmet Aerospace, Inc. | 0.17% | 1.04% |
| Newmont Corp. | 0.15% | 0.48% |
| Cummins, Inc. | 0.15% | 0.95% |
| Fortinet, Inc. | 0.15% | 0.46% |
| Williams Cos., Inc. (The) | 0.14% | 0.44% |
| Datadog, Inc. | 0.13% | 0.84% |
| Constellation Energy Corp. | 0.12% | 0.78% |
| Robinhood Markets, Inc. | 0.12% | 0.77% |
| Coherent Corp. | 0.12% | 0.75% |
| Only in IVV | Only in VO |
|---|---|
| NVIDIA Corp. 7.52% | Seagate Technology Holdings PLC 1.05% |
| Apple, Inc. 6.59% | Bloom Energy Corp 0.79% |
| Microsoft Corp. 4.30% | Cloudflare Inc 0.76% |
| Amazon.com, Inc. 3.62% | Royal Caribbean Cruises Ltd 0.74% |
| Alphabet, Inc. 3.25% | CRH PLC 0.69% |
| Broadcom, Inc. 2.77% | Rocket Lab Corp 0.57% |
| Alphabet, Inc. 2.59% | TE Connectivity PLC 0.57% |
| Micron Technology, Inc. 2.02% | Cheniere Energy Inc 0.49% |
Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026.
| IVV iShares Core S&P 500 ETF | VO Vanguard Mid-Cap Index Fund | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | Vanguard |
| What it is | S&P 500 | Mid-Cap |
| Total return, 1 year | +17.6% | +12.0% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | +0.1 pts | −5.5 pts |
| Expense ratio | 0.03% | 0.03% |
| Already in the S&P 500 | 100.0% | 91.4% |
| Holdings | 504 | 282 |
IVV in plain words
IVV is an index equity fund tracking the S&P 500. Over the year to Sep 11, 2026 it returned +17.6% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.03% a year. By its holdings filed for Jun 30, 2026, 100% of the fund by weight is stocks the S&P 500 also holds, across 504 positions, with the top ten at 36.4%.
VO in plain words
VO is an index equity fund tracking the Mid-Cap. Over the year to Sep 11, 2026 it returned +12.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. By its holdings filed for Jun 30, 2026, 91% of the fund by weight is stocks the S&P 500 also holds, across 282 positions, with the top ten at 9.6%. It sat 4.1% below its high of Aug 14, 2026 on Sep 11, 2026.
Questions people ask
- Which returned more over the last year, IVV or VO?
- In the year to Sep 12, 2026, with distributions reinvested, IVV returned +17.6% and VO returned +12.0%, so IVV returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IVV or VO?
- IVV charges 0.03% a year and VO charges 0.03%, so IVV is cheaper. Fees come from each fund's prospectus.
- How much do IVV and VO overlap with the S&P 500?
- By their latest filed holdings, 100% of IVV and 91% of VO by weight is stocks the S&P 500 already holds. Between the two funds, 15% of their books are the same securities at the same weight.
Other comparisons
Where to next
Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, IVV against VO, data as of Sep 12, 2026. https://etfiq.com/compare/any/IVV-VO Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources