FXNAX vs TSPF: 40% overlap
Fidelity U.S. Bond Index and TSP F Fund — shown via aggregate-bond proxy share 40.0% 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 5 months apart — FXNAX as of 2026-02-28, the rest through 2026-07-23. 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 1.6. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
FXNAX and TSPF hold 829 of the same securities. The ten contributing most to the overlap figure:
| Holding | in FXNAX | in TSPF | Δ |
|---|---|---|---|
| AGENCY-MBS | 16.5% | 24.1% | 7.6% |
| CASH | 1.3% | 2.7% | 1.3% |
| 46647P | 0.6% | 0.5% | 0.0% |
| 06051G | 0.6% | 0.5% | 0.1% |
| 38141G | 0.4% | 0.3% | 0.0% |
| 68389X | 0.4% | 0.3% | 0.0% |
| 95000U | 0.3% | 0.3% | 0.0% |
| 404280 | 0.3% | 0.3% | 0.0% |
| 92343V | 0.3% | 0.3% | 0.0% |
| 172967 | 0.3% | 0.3% | 0.1% |
Where FXNAX 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 | FXNAX | TSPF | Δ |
|---|---|---|---|
| Unclassified | 9.5% | 0.0% | +9.5pp |
| MBS Pass-Through | 16.5% | 24.1% | −7.6pp |
| Cash & Other | 0.0% | -2.1% | +2.1pp |
| Cash and/or Derivatives | 1.3% | 2.7% | −1.3pp |
| Treasuries | 45.4% | 46.5% | −1.1pp |
| Financials | 8.6% | 8.0% | +0.6pp |
| Supranational | 0.4% | 0.9% | −0.5pp |
| CMBS | 0.4% | 0.7% | −0.2pp |
Δ is FXNAX 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
54.9% of FXNAX by weight, held in no part of TSPF.
50.7% of TSPF by weight, held in no part of FXNAX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| FXNAX | TSPF | |
|---|---|---|
| Top 10 holdings | 69.4% | 75.3% |
| Positions held | 1,266 | 1,864 |
| Cost per $10,000 held, per year | $3 | $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 FXNAX and TSPF overlap?
FXNAX and TSPF overlap 40.0% by portfolio weight — moderate overlap. They share 829 holdings. The figure comes from current issuer holdings files (FXNAX as of 2026-02-28, TSPF as of 2026-07-23).
How is the overlap between FXNAX and TSPF calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If FXNAX 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 FXNAX and TSPF?
That depends on your goals — we state facts, not advice. At 40.0% overlap, each fund still contributes meaningfully distinct exposure.
What does FXNAX own that TSPF doesn't?
FXNAX holds 1,266 positions and TSPF holds 1,864; 437 of FXNAX's positions don't appear in TSPF at all, and they are 54.9% of FXNAX by weight.
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Related comparisons
Sources: issuer holdings files, FXNAX as of 2026-02-28, TSPF as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.