SPY vs VSMAX: 3% overlap
SPDR S&P 500 ETF Trust and Vanguard Small-Cap Index Admiral share 3.1% 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
SPY and VSMAX hold 129 of the same securities. The ten contributing most to the overlap figure:
| Holding | in SPY | in VSMAX | Δ |
|---|---|---|---|
| FLEX | 0.1% | 0.4% | 0.3% |
| EME | 0.1% | 0.4% | 0.4% |
| JBL | 0.1% | 0.5% | 0.4% |
| EQT | 0.1% | 0.2% | 0.1% |
| STLD | 0.1% | 0.2% | 0.1% |
| CASY | 0.1% | 0.4% | 0.3% |
| NRG | 0.0% | 0.4% | 0.3% |
| CNC | 0.0% | 0.2% | 0.1% |
| ATO | 0.0% | 0.3% | 0.3% |
| Q | 0.0% | 0.2% | 0.2% |
Where SPY and VSMAX 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 | SPY | VSMAX | Δ |
|---|---|---|---|
| Information Technology | 37.5% | 16.1% | +21.4pp |
| Industrials | 8.9% | 21.0% | −12.1pp |
| Communication Services | 9.3% | 3.0% | +6.3pp |
| Real Estate | 1.9% | 7.1% | −5.2pp |
| Materials | 1.8% | 5.3% | −3.5pp |
| Health Care | 9.1% | 11.9% | −2.8pp |
| Cash and/or Derivatives | 0.0% | 1.7% | −1.7pp |
| Consumer Discretionary | 8.8% | 9.9% | −1.2pp |
Δ is SPY minus VSMAX, 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
96.8% of SPY by weight, held in no part of VSMAX.
78.7% of VSMAX by weight, held in no part of SPY.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| SPY | VSMAX | |
|---|---|---|
| Top 10 holdings | 36.9% | 5.6% |
| Positions held | 505 | 1,308 |
| Cost per $10,000 held, per year | $9 | $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 SPY and VSMAX overlap?
SPY and VSMAX overlap 3.1% by portfolio weight — largely distinct portfolios. They share 129 holdings. The figure comes from current issuer holdings files (SPY as of 2026-07-23, VSMAX as of 2026-06-30).
How is the overlap between SPY and VSMAX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If SPY holds a stock at 6% and VSMAX 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 SPY and VSMAX?
That depends on your goals — we state facts, not advice. At 3.1% overlap, each fund still contributes meaningfully distinct exposure.
What does SPY own that VSMAX doesn't?
SPY holds 505 positions and VSMAX holds 1,308; 375 of SPY's positions don't appear in VSMAX at all, and they are 96.8% of SPY by weight.
You probably hold more than two funds
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Related comparisons
Sources: issuer holdings files, SPY as of 2026-07-23, VSMAX as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.