VIMAX vs VOO: 17% overlap
Vanguard Mid-Cap Index Admiral and Vanguard S&P 500 ETF share 16.6% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
You would hold two tickers and get the diversification of 1.8. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
VIMAX and VOO hold 249 of the same securities. The ten contributing most to the overlap figure:
| Holding | in VIMAX | in VOO | Δ |
|---|---|---|---|
| WDC | 1.1% | 0.3% | 0.7% |
| STX | 1.0% | 0.3% | 0.7% |
| CASH | 0.5% | 0.2% | 0.3% |
| VRT | 1.2% | 0.2% | 1.0% |
| PWR | 1.0% | 0.2% | 0.9% |
| HWM | 1.0% | 0.2% | 0.9% |
| NEM | 0.5% | 0.2% | 0.3% |
| CMI | 1.0% | 0.2% | 0.8% |
| FTNT | 0.5% | 0.1% | 0.3% |
| WMB | 0.4% | 0.1% | 0.3% |
Where VIMAX and VOO differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | VIMAX | VOO | Δ |
|---|---|---|---|
| Information Technology | 16.1% | 38.0% | −21.9pp |
| Industrials | 19.6% | 8.9% | +10.7pp |
| Communication Services | 2.8% | 9.7% | −6.9pp |
| Utilities | 8.4% | 2.2% | +6.2pp |
| Energy | 7.3% | 3.0% | +4.3pp |
| Real Estate | 5.1% | 1.8% | +3.2pp |
| Materials | 4.3% | 1.8% | +2.5pp |
| Financials | 14.0% | 11.6% | +2.4pp |
Δ is VIMAX minus VOO, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
8.6% of VIMAX by weight, held in no part of VOO.
83.4% of VOO by weight, held in no part of VIMAX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| VIMAX | VOO | |
|---|---|---|
| Top 10 holdings | 9.5% | 36.4% |
| Positions held | 283 | 505 |
| Cost per $10,000 held, per year | $5 | $3 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do VIMAX and VOO overlap?
VIMAX and VOO overlap 16.6% by portfolio weight — moderate overlap. They share 249 holdings. The figure comes from current issuer holdings files (VIMAX as of 2026-06-30, VOO as of 2026-06-30).
How is the overlap between VIMAX and VOO calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If VIMAX holds a stock at 6% and VOO holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both VIMAX and VOO?
That depends on your goals — we state facts, not advice. At 16.6% overlap, each fund still contributes meaningfully distinct exposure.
What does VIMAX own that VOO doesn't?
VIMAX holds 283 positions and VOO holds 505; 34 of VIMAX's positions don't appear in VOO at all, and they are 8.6% of VIMAX by weight.
You probably hold more than two funds
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Related comparisons
Sources: issuer holdings files, VIMAX as of 2026-06-30, VOO as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.