TLT vs TSPF: 9% overlap
iShares 20+ Year Treasury Bond ETF and TSP F Fund — shown via aggregate-bond proxy share 9.3% 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
TLT and TSPF hold 2 of the same securities. The ten contributing most to the overlap figure:
| Holding | in TLT | in TSPF | Δ |
|---|---|---|---|
| UST-10Y+ | 100.0% | 9.3% | 90.7% |
| CASH | 0.0% | 2.7% | 2.7% |
Where TLT and TSPF 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 | TLT | TSPF | Δ |
|---|---|---|---|
| Treasuries | 100.0% | 46.5% | +53.5pp |
| MBS Pass-Through | 0.0% | 24.1% | −24.1pp |
| Corporate — industrial & other | 0.0% | 14.3% | −14.3pp |
| Financials | 0.0% | 8.0% | −8.0pp |
| Cash and/or Derivatives | 0.0% | 2.7% | −2.7pp |
| Utilities | 0.0% | 2.5% | −2.5pp |
| Cash & Other | -0.0% | -2.1% | +2.1pp |
| Sovereign | 0.0% | 1.1% | −1.1pp |
Δ is TLT minus TSPF, 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
0.0% of TLT by weight, held in no part of TSPF.
90.1% of TSPF by weight, held in no part of TLT.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| TLT | TSPF | |
|---|---|---|
| Top 10 holdings | 100.0% | 75.3% |
| Positions held | 3 | 1,864 |
| Cost per $10,000 held, per year | $15 | $5 |
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 TLT and TSPF overlap?
TLT and TSPF overlap 9.3% by portfolio weight — largely distinct portfolios. They share 2 holdings. The figure comes from current issuer holdings files (TLT as of 2026-07-23, TSPF as of 2026-07-23).
How is the overlap between TLT and TSPF calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If TLT holds a stock at 6% and TSPF 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 TLT and TSPF?
That depends on your goals — we state facts, not advice. At 9.3% overlap, each fund still contributes meaningfully distinct exposure.
What does TLT own that TSPF doesn't?
TLT holds 3 positions and TSPF holds 1,864; 0 of TLT's positions don't appear in TSPF at all, and they are 0.0% of TLT by weight.
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Related comparisons
Sources: issuer holdings files, TLT as of 2026-07-23, TSPF as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.