ITOT vs TSPC: 88% overlap
iShares Core S&P Total U.S. Stock Market ETF and TSP C Fund — shown via S&P 500 proxy share 88.4% 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 1.1. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
ITOT and TSPC hold 505 of the same securities. The ten contributing most to the overlap figure:
| Holding | in ITOT | in TSPC | Δ |
|---|---|---|---|
| NVDA | 7.0% | 7.5% | 0.5% |
| AAPL | 6.6% | 6.6% | 0.0% |
| MSFT | 3.9% | 4.3% | 0.4% |
| AMZN | 3.2% | 3.6% | 0.4% |
| GOOGL | 2.6% | 3.2% | 0.7% |
| AVGO | 2.6% | 2.8% | 0.2% |
| GOOG | 2.1% | 2.6% | 0.5% |
| META | 1.8% | 1.9% | 0.1% |
| MU | 1.6% | 2.0% | 0.5% |
| LLY | 1.3% | 1.5% | 0.2% |
Where ITOT and TSPC 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 | TSPC | Δ |
|---|---|---|---|
| Information Technology | 35.2% | 38.0% | −2.8pp |
| Industrials | 10.1% | 8.9% | +1.2pp |
| Financials | 12.7% | 11.6% | +1.1pp |
| Communication Services | 8.7% | 9.7% | −1.0pp |
| Health Care | 9.7% | 8.9% | +0.8pp |
| Energy | 3.5% | 3.0% | +0.6pp |
| Consumer Discretionary | 8.8% | 9.3% | −0.5pp |
| Real Estate | 2.3% | 1.8% | +0.5pp |
Δ is ITOT minus TSPC, 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
11.4% of ITOT by weight, held in no part of TSPC.
0.0% of TSPC 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 | TSPC | |
|---|---|---|
| Top 10 holdings | 32.7% | 36.4% |
| Positions held | 2,440 | 505 |
| 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 TSPC overlap?
ITOT and TSPC overlap 88.4% by portfolio weight — substantial duplication if you hold both. They share 505 holdings. The figure comes from current issuer holdings files (ITOT as of 2026-07-23, TSPC as of 2026-06-30).
How is the overlap between ITOT and TSPC 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 TSPC 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 TSPC?
That depends on your goals — we state facts, not advice. At 88.4% overlap, most of what one fund holds, the other holds too. Expense ratios: ITOT 0.03% versus TSPC 0.05%.
What does ITOT own that TSPC doesn't?
ITOT holds 2,440 positions and TSPC holds 505; 1,934 of ITOT's positions don't appear in TSPC at all, and they are 11.4% of ITOT by weight.
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Related comparisons
Sources: issuer holdings files, ITOT as of 2026-07-23, TSPC as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.