TSPI vs VTWNX: 16% overlap
TSP I Fund — shown via international proxy and Vanguard Target Retirement 2020 share 15.7% 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 3 months apart — VTWNX as of 2026-03-31, the rest through 2026-06-30. 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 1.8. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
TSPI and VTWNX hold 8,453 of the same securities. The ten contributing most to the overlap figure:
| Holding | in TSPI | in VTWNX | Δ |
|---|---|---|---|
| CASH | 2.4% | 1.7% | 0.8% |
| 2330 | 4.3% | 0.6% | 3.7% |
| 005930 | 2.3% | 0.3% | 2.0% |
| 000660 | 2.2% | 0.3% | 1.9% |
| ASML | 1.7% | 0.2% | 1.5% |
| 700 | 0.8% | 0.1% | 0.7% |
| HSBA | 0.7% | 0.1% | 0.6% |
| ROP | 0.6% | 0.1% | 0.5% |
| RY | 0.6% | 0.1% | 0.6% |
| SAN | 0.7% | 0.1% | 0.6% |
Where TSPI and VTWNX 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 | TSPI | VTWNX | Δ |
|---|---|---|---|
| Unclassified | 9.1% | 29.8% | −20.6pp |
| Treasuries | 0.0% | 17.1% | −17.1pp |
| Financials | 19.7% | 8.2% | +11.5pp |
| Information Technology | 20.9% | 10.0% | +10.9pp |
| Industrials | 13.8% | 4.0% | +9.8pp |
| MBS Pass-Through | 0.0% | 7.2% | −7.2pp |
| Corporate — industrial & other | 0.0% | 5.5% | −5.5pp |
| Consumer Discretionary | 7.5% | 2.9% | +4.6pp |
Δ is TSPI minus VTWNX, 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 TSPI by weight, held in no part of VTWNX.
83.1% of VTWNX by weight, held in no part of TSPI.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| TSPI | VTWNX | |
|---|---|---|
| Top 10 holdings | 16.3% | 44.9% |
| Positions held | 8,453 | 7 |
| Cost per $10,000 held, per year | $5 | $8 |
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 TSPI and VTWNX overlap?
TSPI and VTWNX overlap 15.7% by portfolio weight — moderate overlap. They share 8,453 holdings. The figure comes from current issuer holdings files (TSPI as of 2026-06-30, VTWNX as of 2026-03-31).
How is the overlap between TSPI and VTWNX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If TSPI holds a stock at 6% and VTWNX 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 TSPI and VTWNX?
That depends on your goals — we state facts, not advice. At 15.7% overlap, each fund still contributes meaningfully distinct exposure.
What does TSPI own that VTWNX doesn't?
TSPI holds 8,453 positions and VTWNX holds 7; 0 of TSPI's positions don't appear in VTWNX at all, and they are 0.0% of TSPI by weight.
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Related comparisons
Sources: issuer holdings files, TSPI as of 2026-06-30, VTWNX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.