FSKAX vs ITOT: 88% overlap
Fidelity Total Market Index and iShares Core S&P Total U.S. Stock Market ETF share 88.3% 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 5 months apart — FSKAX as of 2026-02-28, the rest through 2026-07-23. 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 1.1. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
FSKAX and ITOT hold 2,259 of the same securities. The ten contributing most to the overlap figure:
| Holding | in FSKAX | in ITOT | Δ |
|---|---|---|---|
| NVDA | 6.5% | 7.0% | 0.6% |
| AAPL | 5.9% | 6.6% | 0.7% |
| MSFT | 4.4% | 3.9% | 0.4% |
| AMZN | 3.1% | 3.2% | 0.1% |
| GOOGL | 2.7% | 2.6% | 0.1% |
| AVGO | 2.3% | 2.6% | 0.3% |
| GOOG | 2.2% | 2.1% | 0.1% |
| META | 2.1% | 1.8% | 0.3% |
| LLY | 1.3% | 1.3% | 0.0% |
| BRK-B | 1.4% | 1.3% | 0.1% |
Where FSKAX and ITOT 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 | FSKAX | ITOT | Δ |
|---|---|---|---|
| Information Technology | 29.9% | 35.2% | −5.3pp |
| Unclassified | 4.0% | 0.0% | +4.0pp |
| Communication Services | 9.7% | 8.7% | +1.0pp |
| Consumer Discretionary | 9.6% | 8.8% | +0.8pp |
| Consumer Staples | 5.1% | 4.4% | +0.7pp |
| Industrials | 9.6% | 10.1% | −0.5pp |
| Cash and/or Derivatives | 0.7% | 0.2% | +0.5pp |
| Financials | 12.2% | 12.7% | −0.5pp |
Δ is FSKAX minus ITOT, 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
4.2% of FSKAX by weight, held in no part of ITOT.
3.7% of ITOT by weight, held in no part of FSKAX.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| FSKAX | ITOT | |
|---|---|---|
| Top 10 holdings | 32.1% | 32.7% |
| Positions held | 3,754 | 2,440 |
| Cost per $10,000 held, per year | $1 | $3 |
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 FSKAX and ITOT overlap?
FSKAX and ITOT overlap 88.3% by portfolio weight — substantial duplication if you hold both. They share 2,259 holdings. The figure comes from current issuer holdings files (FSKAX as of 2026-02-28, ITOT as of 2026-07-23).
How is the overlap between FSKAX and ITOT calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If FSKAX holds a stock at 6% and ITOT 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 FSKAX and ITOT?
That depends on your goals — we state facts, not advice. At 88.3% overlap, most of what one fund holds, the other holds too. Expense ratios: FSKAX 0.01% versus ITOT 0.03%.
What does FSKAX own that ITOT doesn't?
FSKAX holds 3,754 positions and ITOT holds 2,440; 1,494 of FSKAX's positions don't appear in ITOT at all, and they are 4.2% of FSKAX by weight.
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Related comparisons
Sources: issuer holdings files, FSKAX as of 2026-02-28, ITOT as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.