FZROX vs VO: 15% overlap
Fidelity ZERO Total Market Index and Vanguard Mid-Cap ETF share 15.3% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 2 months apart — FZROX as of 2026-04-30, the rest through 2026-06-30. Each fund is compared using its most recent file, so any trading in between shows up as a difference.
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
FZROX and VO hold 264 of the same securities. The ten contributing most to the overlap figure:
| Holding | in FZROX | in VO | Δ |
|---|---|---|---|
| CASH | 0.6% | 0.5% | 0.2% |
| WDC | 0.2% | 1.1% | 0.9% |
| VRT | 0.2% | 1.2% | 1.0% |
| NEM | 0.2% | 0.5% | 0.3% |
| PWR | 0.2% | 1.0% | 0.9% |
| CEG | 0.1% | 0.8% | 0.6% |
| HWM | 0.1% | 1.0% | 0.9% |
| WMB | 0.1% | 0.4% | 0.3% |
| CMI | 0.1% | 1.0% | 0.8% |
| FDX | 0.1% | 0.3% | 0.2% |
Where FZROX and VO 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 | FZROX | VO | Δ |
|---|---|---|---|
| Information Technology | 32.3% | 16.1% | +16.2pp |
| Industrials | 9.2% | 19.6% | −10.4pp |
| Communication Services | 10.1% | 2.8% | +7.4pp |
| Utilities | 2.3% | 8.4% | −6.1pp |
| Energy | 3.5% | 7.3% | −3.8pp |
| Unclassified | 3.8% | 0.4% | +3.3pp |
| Real Estate | 2.3% | 5.1% | −2.8pp |
| Materials | 1.6% | 4.3% | −2.7pp |
Δ is FZROX minus VO, 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
84.9% of FZROX by weight, held in no part of VO.
6.6% of VO by weight, held in no part of FZROX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| FZROX | VO | |
|---|---|---|
| Top 10 holdings | 34.0% | 9.5% |
| Positions held | 2,685 | 283 |
| Cost per $10,000 held, per year | $0 | $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 FZROX and VO overlap?
FZROX and VO overlap 15.3% by portfolio weight — moderate overlap. They share 264 holdings. The figure comes from current issuer holdings files (FZROX as of 2026-04-30, VO as of 2026-06-30).
How is the overlap between FZROX and VO calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If FZROX holds a stock at 6% and VO 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 FZROX and VO?
That depends on your goals — we state facts, not advice. At 15.3% overlap, each fund still contributes meaningfully distinct exposure.
What does FZROX own that VO doesn't?
FZROX holds 2,685 positions and VO holds 283; 2,420 of FZROX's positions don't appear in VO at all, and they are 84.9% of FZROX by weight.
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Related comparisons
Sources: issuer holdings files, FZROX as of 2026-04-30, VO as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.