SOXX vs TSPS: 2% overlap
iShares Semiconductor ETF and TSP S Fund — shown via extended-market proxy share 2.1% 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
SOXX and TSPS hold 7 of the same securities. The ten contributing most to the overlap figure:
| Holding | in SOXX | in TSPS | Δ |
|---|---|---|---|
| ALAB | 2.4% | 0.7% | 1.6% |
| CRDO | 2.0% | 0.5% | 1.5% |
| ENTG | 1.1% | 0.3% | 0.8% |
| MTSI | 1.0% | 0.3% | 0.7% |
| RMBS | 0.6% | 0.2% | 0.4% |
| CASH | 0.1% | 3.8% | 3.7% |
| MRVL | 4.3% | 0.0% | 4.3% |
Where SOXX and TSPS 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 | SOXX | TSPS | Δ |
|---|---|---|---|
| Information Technology | 99.9% | 17.6% | +82.2pp |
| Industrials | 0.0% | 19.8% | −19.8pp |
| Financials | 0.0% | 13.9% | −13.9pp |
| Health Care | 0.0% | 13.2% | −13.2pp |
| Consumer Discretionary | 0.0% | 8.8% | −8.8pp |
| Real Estate | 0.0% | 4.8% | −4.8pp |
| Communication Services | 0.0% | 4.5% | −4.5pp |
| Materials | 0.0% | 4.1% | −4.1pp |
Δ is SOXX minus TSPS, 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
88.5% of SOXX by weight, held in no part of TSPS.
94.2% of TSPS by weight, held in no part of SOXX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| SOXX | TSPS | |
|---|---|---|
| Top 10 holdings | 60.9% | 10.6% |
| Positions held | 32 | 3,327 |
| Cost per $10,000 held, per year | $34 | $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 SOXX and TSPS overlap?
SOXX and TSPS overlap 2.1% by portfolio weight — largely distinct portfolios. They share 7 holdings. The figure comes from current issuer holdings files (SOXX as of 2026-07-23, TSPS as of 2026-06-30).
How is the overlap between SOXX and TSPS calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If SOXX holds a stock at 6% and TSPS 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 SOXX and TSPS?
That depends on your goals — we state facts, not advice. At 2.1% overlap, each fund still contributes meaningfully distinct exposure.
What does SOXX own that TSPS doesn't?
SOXX holds 32 positions and TSPS holds 3,327; 24 of SOXX's positions don't appear in TSPS at all, and they are 88.5% of SOXX by weight.
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Related comparisons
Sources: issuer holdings files, SOXX as of 2026-07-23, TSPS as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.