BND vs TLT: 10% overlap
Vanguard Total Bond Market ETF and iShares 20+ Year Treasury Bond ETF share 10.2% 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 1.9. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
BND and TLT hold 2 of the same securities. The ten contributing most to the overlap figure:
| Holding | in BND | in TLT | Δ |
|---|---|---|---|
| UST-10Y+ | 10.2% | 100.0% | 89.8% |
| CASH | 1.1% | 0.0% | 1.1% |
Where BND and TLT 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 | BND | TLT | Δ |
|---|---|---|---|
| Treasuries | 48.2% | 100.0% | −51.8pp |
| MBS Pass-Through | 20.3% | 0.0% | +20.3pp |
| Corporate — industrial & other | 14.6% | 0.0% | +14.6pp |
| Financials | 7.9% | 0.0% | +7.9pp |
| Utilities | 2.6% | 0.0% | +2.6pp |
| Supranational | 1.4% | 0.0% | +1.4pp |
| Sovereign | 1.2% | 0.0% | +1.2pp |
| Cash and/or Derivatives | 1.1% | 0.0% | +1.1pp |
Δ is BND minus TLT, 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
88.7% of BND by weight, held in no part of TLT.
0.0% of TLT by weight, held in no part of BND.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| BND | TLT | |
|---|---|---|
| Top 10 holdings | 71.7% | 100.0% |
| Positions held | 2,047 | 3 |
| Cost per $10,000 held, per year | $3 | $15 |
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 BND and TLT overlap?
BND and TLT overlap 10.2% by portfolio weight — largely distinct portfolios. They share 2 holdings. The figure comes from current issuer holdings files (BND as of 2026-06-30, TLT as of 2026-07-23).
How is the overlap between BND and TLT calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If BND holds a stock at 6% and TLT 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 BND and TLT?
That depends on your goals — we state facts, not advice. At 10.2% overlap, each fund still contributes meaningfully distinct exposure.
What does BND own that TLT doesn't?
BND holds 2,047 positions and TLT holds 3; 2,045 of BND's positions don't appear in TLT at all, and they are 88.7% of BND by weight.
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Related comparisons
Sources: issuer holdings files, BND as of 2026-06-30, TLT as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.