MUB vs TSPF: 0% overlap
iShares National Muni Bond ETF and TSP F Fund — shown via aggregate-bond proxy share 0.2% 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 2.0. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
MUB and TSPF hold 74 of the same securities. The ten contributing most to the overlap figure:
| Holding | in MUB | in TSPF | Δ |
|---|---|---|---|
| 73358W | 0.2% | 0.0% | 0.2% |
| 13063D | 2.7% | 0.0% | 2.7% |
| 64966S | 1.1% | 0.0% | 1.1% |
| 646139 | 0.1% | 0.0% | 0.1% |
| 13063E | 1.2% | 0.0% | 1.2% |
| 072024 | 0.4% | 0.0% | 0.4% |
| 64972F | 0.1% | 0.0% | 0.1% |
| 626207 | 0.0% | 0.0% | 0.0% |
| 914455 | 0.0% | 0.0% | 0.0% |
| 91412H | 1.6% | 0.0% | 1.6% |
Where MUB 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 | MUB | TSPF | Δ |
|---|---|---|---|
| Treasuries | 0.0% | 46.5% | −46.5pp |
| State Tax-Backed | 30.7% | 0.0% | +30.6pp |
| MBS Pass-Through | 0.0% | 24.1% | −24.1pp |
| Local Tax-Backed | 14.9% | 0.0% | +14.9pp |
| Corporate — industrial & other | 0.0% | 14.3% | −14.3pp |
| Utilities | 16.8% | 2.5% | +14.2pp |
| School Districts | 10.2% | 0.0% | +10.2pp |
| Transportation | 10.2% | 0.1% | +10.1pp |
Δ is MUB 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
77.2% of MUB by weight, held in no part of TSPF.
99.2% of TSPF by weight, held in no part of MUB.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| MUB | TSPF | |
|---|---|---|
| Top 10 holdings | 17.2% | 75.3% |
| Positions held | 969 | 1,864 |
| Cost per $10,000 held, per year | $5 | $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 MUB and TSPF overlap?
MUB and TSPF overlap 0.2% by portfolio weight — largely distinct portfolios. They share 74 holdings. The figure comes from current issuer holdings files (MUB as of 2026-07-23, TSPF as of 2026-07-23).
How is the overlap between MUB and TSPF calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If MUB 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 MUB and TSPF?
That depends on your goals — we state facts, not advice. At 0.2% overlap, each fund still contributes meaningfully distinct exposure.
What does MUB own that TSPF doesn't?
MUB holds 969 positions and TSPF holds 1,864; 894 of MUB's positions don't appear in TSPF at all, and they are 77.2% of MUB by weight.
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Related comparisons
Sources: issuer holdings files, MUB as of 2026-07-23, TSPF as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.