BIV vs FXNAX: 23% overlap
Vanguard Intermediate-Term Bond ETF and Fidelity U.S. Bond Index share 23.2% 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 4 months apart — FXNAX as of 2026-02-28, 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
BIV and FXNAX hold 578 of the same securities. The ten contributing most to the overlap figure:
| Holding | in BIV | in FXNAX | Δ |
|---|---|---|---|
| 06051G | 0.9% | 0.6% | 0.3% |
| 46647P | 1.1% | 0.6% | 0.5% |
| 38141G | 0.6% | 0.4% | 0.2% |
| 68389X | 0.5% | 0.4% | 0.1% |
| AGENCY-MBS | 0.3% | 16.5% | 16.2% |
| 172967 | 0.3% | 0.3% | 0.0% |
| 95000U | 0.6% | 0.3% | 0.3% |
| 404280 | 0.6% | 0.3% | 0.4% |
| 92343V | 0.4% | 0.3% | 0.1% |
| CASH | 0.3% | 1.3% | 1.1% |
Where BIV and FXNAX 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 | BIV | FXNAX | Δ |
|---|---|---|---|
| MBS Pass-Through | 0.3% | 16.5% | −16.2pp |
| Treasuries | 55.9% | 45.4% | +10.5pp |
| Unclassified | 0.2% | 9.5% | −9.3pp |
| Corporate — industrial & other | 20.2% | 14.1% | +6.0pp |
| Financials | 14.3% | 8.6% | +5.7pp |
| Supranational | 1.8% | 0.4% | +1.4pp |
| Utilities | 3.9% | 2.5% | +1.4pp |
| Cash and/or Derivatives | 0.3% | 1.3% | −1.1pp |
Δ is BIV minus FXNAX, 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
61.0% of BIV by weight, held in no part of FXNAX.
58.5% of FXNAX by weight, held in no part of BIV.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| BIV | FXNAX | |
|---|---|---|
| Top 10 holdings | 62.1% | 69.4% |
| Positions held | 854 | 1,266 |
| Cost per $10,000 held, per year | $3 | $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 BIV and FXNAX overlap?
BIV and FXNAX overlap 23.2% by portfolio weight — moderate overlap. They share 578 holdings. The figure comes from current issuer holdings files (BIV as of 2026-06-30, FXNAX as of 2026-02-28).
How is the overlap between BIV and FXNAX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If BIV holds a stock at 6% and FXNAX 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 BIV and FXNAX?
That depends on your goals — we state facts, not advice. At 23.2% overlap, each fund still contributes meaningfully distinct exposure.
What does BIV own that FXNAX doesn't?
BIV holds 854 positions and FXNAX holds 1,266; 276 of BIV's positions don't appear in FXNAX at all, and they are 61.0% of BIV by weight.
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Related comparisons
Sources: issuer holdings files, BIV as of 2026-06-30, FXNAX as of 2026-02-28. Weights are fractions of each fund. Diagnostics, not advice.