ETF comparison
VIOO vs VO
US Small Cap vs US Mid Cap.
Vanguard S&P Small-Cap 600 Index Fund ETF Shares · Vanguard Morningstar Mid-Cap ETF
Holdings overlap
0 positions appear in both funds. Buying equal dollars of VIOO and VO would leave roughly 0.0% of each dollar exposed to the same underlying securities.
Unmatched is the part of a fund's weight the other fund doesn't match: names only it holds, plus any extra weight it puts in names both funds hold.
Side by side
Sub-score comparison
Tracking quality isn't part of the composite — see what we don't score for why.
Cost difference
VO is 4 bps cheaper than VIOO. On a $100,000 position that's about $40/yr more in fees for VIOO.
Fee figure is the annual expense charged on $100,000. To see how the gap compounds over a multi-decade holding period, open the cost calculator pre-filled with VIOO vs VO.
Top shared holdings
0 shared in totalNo shared holdings between these funds.
Only in VIOO
603 total- Sanmina Corp 0.83%
- Semtech Corp 0.83%
- Viavi Solutions Inc 0.66%
- Viasat Inc 0.64%
- Lumen Technologies Inc 0.61%
- FormFactor Inc 0.57%
- Element Solutions Inc 0.57%
- Argan Inc 0.54%
- Enphase Energy Inc 0.53%
- Molina Healthcare Inc 0.53%
Only in VO
282 total- Vertiv Holdings Co 1.22%
- Western Digital Corp 1.06%
- Seagate Technology Holdings PLC 1.05%
- Quanta Services Inc 1.04%
- Howmet Aerospace Inc 1.04%
- Cummins Inc 0.95%
- Datadog Inc 0.83%
- Bloom Energy Corp 0.79%
- Constellation Energy Corp 0.78%
- Robinhood Markets Inc 0.77%
Related comparisons
More comparisons with VIOO
- VIOO vs VOO · Vanguard S&P 500 ETF 0.0%
- VIOO vs VTV · Vanguard Morningstar Value ETF 0.0%
- VIOO vs VUG · Vanguard Morningstar Growth ETF 0.0%
- VIOO vs SPSM · State Street SPDR Portfolio S&P 600 Small Cap ETF 91.4%
- VIOO vs IJR · iShares Core S&P Small-Cap ETF 90.2%
- VIOO vs VIOV · Vanguard S&P Small-Cap 600 Value Index Fund ETF Shares 64.2%
More comparisons with VO
- VO vs VIOV · Vanguard S&P Small-Cap 600 Value Index Fund ETF Shares 0.0%
- VO vs VYMI · Vanguard International High Dividend Yield Index Fund ETF Shares 0.0%
- VO vs XLG · Invesco S&P 500 Top 50 ETF 0.0%
- VO vs VOE · Vanguard Morningstar Mid-Cap Value ETF 56.8%
- VO vs IWR · iShares Russell Mid-Cap ETF 54.8%
- VO vs IWS · iShares Russell Mid-Cap Value ETF 52.6%
Percentages are holdings overlap with the named fund.
Open VIOO or VO at a brokerage
Both funds trade commission-free at major US brokerages.
Affiliate links — opening an account through these earns PlainIndex a one-time referral. Scoring is computed before any affiliate consideration; see our methodology and funding disclosure.
Holdings overlap is the sum of min(weight_a, weight_b) over positions
matched on ISIN (CUSIP fallback). Methodology: see
/methodology/.
Comparing two funds doesn't endorse swapping one for the other. Tax-lot history, account type, and personal goals matter — PlainIndex publishes data and methodology, not investment advice.