BIV vs VBTLX: 46% overlap
Vanguard Intermediate-Term Bond ETF and Vanguard Total Bond Market Index Admiral share 46.1% 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 1.5. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
BIV and VBTLX hold 838 of the same securities. The ten contributing most to the overlap figure:
| Holding | in BIV | in VBTLX | Δ |
|---|---|---|---|
| UST-3-10Y | 55.9% | 21.3% | 34.7% |
| 46647P | 1.1% | 0.6% | 0.5% |
| 06051G | 0.9% | 0.5% | 0.4% |
| 459058 | 0.4% | 0.4% | 0.0% |
| 68389X | 0.5% | 0.3% | 0.1% |
| AGENCY-MBS | 0.3% | 20.3% | 20.0% |
| 298785 | 0.6% | 0.3% | 0.2% |
| 38141G | 0.6% | 0.3% | 0.3% |
| 023135 | 0.4% | 0.3% | 0.1% |
| 00206R | 0.3% | 0.3% | 0.0% |
Where BIV and VBTLX 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 | VBTLX | Δ |
|---|---|---|---|
| MBS Pass-Through | 0.3% | 20.3% | −20.0pp |
| Treasuries | 55.9% | 48.2% | +7.8pp |
| Financials | 14.3% | 7.9% | +6.4pp |
| Corporate — industrial & other | 20.2% | 14.6% | +5.5pp |
| Utilities | 3.9% | 2.6% | +1.2pp |
| Cash and/or Derivatives | 0.3% | 1.1% | −0.9pp |
| Sovereign | 1.9% | 1.2% | +0.7pp |
| Unclassified | 0.2% | 0.7% | −0.5pp |
Δ is BIV minus VBTLX, 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
0.2% of BIV by weight, held in no part of VBTLX.
31.7% of VBTLX 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 | VBTLX | |
|---|---|---|
| Top 10 holdings | 62.1% | 71.7% |
| Positions held | 854 | 2,047 |
| Cost per $10,000 held, per year | $3 | $4 |
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 VBTLX overlap?
BIV and VBTLX overlap 46.1% by portfolio weight — moderate overlap. They share 838 holdings. The figure comes from current issuer holdings files (BIV as of 2026-06-30, VBTLX as of 2026-06-30).
How is the overlap between BIV and VBTLX 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 VBTLX 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 VBTLX?
That depends on your goals — we state facts, not advice. At 46.1% overlap, each fund still contributes meaningfully distinct exposure.
What does BIV own that VBTLX doesn't?
BIV holds 854 positions and VBTLX holds 2,047; 16 of BIV's positions don't appear in VBTLX at all, and they are 0.2% of BIV by weight.
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Related comparisons
Sources: issuer holdings files, BIV as of 2026-06-30, VBTLX as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.