ITOT vs TSPS: 12% overlap
iShares Core S&P Total U.S. Stock Market ETF and TSP S Fund — shown via extended-market proxy share 11.5% 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
ITOT and TSPS hold 1,923 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ITOT | in TSPS | Δ |
|---|---|---|---|
| CASH | 0.2% | 3.8% | 3.6% |
| SNOW | 0.1% | 1.0% | 0.9% |
| NET | 0.1% | 0.9% | 0.8% |
| SPCX | 0.1% | 1.1% | 1.0% |
| BE | 0.1% | 0.9% | 0.8% |
| LNG | 0.1% | 0.6% | 0.5% |
| FERG | 0.1% | 0.5% | 0.5% |
| ALAB | 0.1% | 0.7% | 0.7% |
| CRDO | 0.1% | 0.5% | 0.4% |
| NTRA | 0.1% | 0.4% | 0.4% |
Where ITOT 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 | ITOT | TSPS | Δ |
|---|---|---|---|
| Information Technology | 35.2% | 17.6% | +17.5pp |
| Industrials | 10.1% | 19.8% | −9.7pp |
| Communication Services | 8.7% | 4.5% | +4.3pp |
| Cash and/or Derivatives | 0.2% | 3.8% | −3.6pp |
| Health Care | 9.7% | 13.2% | −3.5pp |
| Real Estate | 2.3% | 4.8% | −2.5pp |
| Materials | 2.1% | 4.1% | −2.0pp |
| Consumer Staples | 4.4% | 2.7% | +1.7pp |
Δ is ITOT 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
88.1% of ITOT by weight, held in no part of TSPS.
2.4% of TSPS by weight, held in no part of ITOT.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| ITOT | TSPS | |
|---|---|---|
| Top 10 holdings | 32.7% | 10.6% |
| Positions held | 2,440 | 3,327 |
| 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 ITOT and TSPS overlap?
ITOT and TSPS overlap 11.5% by portfolio weight — largely distinct portfolios. They share 1,923 holdings. The figure comes from current issuer holdings files (ITOT as of 2026-07-23, TSPS as of 2026-06-30).
How is the overlap between ITOT and TSPS calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If ITOT 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 ITOT and TSPS?
That depends on your goals — we state facts, not advice. At 11.5% overlap, each fund still contributes meaningfully distinct exposure.
What does ITOT own that TSPS doesn't?
ITOT holds 2,440 positions and TSPS holds 3,327; 516 of ITOT's positions don't appear in TSPS at all, and they are 88.1% of ITOT by weight.
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Related comparisons
Sources: issuer holdings files, ITOT as of 2026-07-23, TSPS as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.