SPYM vs VONG: 55% overlap
State Street SPDR Portfolio S&P 500 ETF and Vanguard Russell 1000 Growth ETF share 54.8% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published 27 days apart — VONG as of 2026-06-30, the rest through 2026-07-27. 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 1.5. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
SPYM and VONG hold 178 of the same securities. The ten contributing most to the overlap figure:
| Holding | in SPYM | in VONG | Δ |
|---|---|---|---|
| NVDA | 7.5% | 13.8% | 6.4% |
| AAPL | 7.8% | 6.7% | 1.0% |
| MSFT | 4.5% | 4.1% | 0.4% |
| GOOGL | 3.0% | 6.2% | 3.2% |
| AVGO | 2.8% | 5.2% | 2.4% |
| GOOG | 2.4% | 5.0% | 2.6% |
| META | 2.0% | 3.0% | 1.0% |
| MU | 1.6% | 3.9% | 2.3% |
| LLY | 1.5% | 2.8% | 1.4% |
| TSLA | 1.4% | 3.6% | 2.3% |
Where SPYM and VONG 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 | SPYM | VONG | Δ |
|---|---|---|---|
| Information Technology | 36.8% | 54.3% | −17.5pp |
| Financials | 12.6% | 4.3% | +8.3pp |
| Communication Services | 9.5% | 16.1% | −6.6pp |
| Health Care | 9.2% | 5.4% | +3.8pp |
| Consumer Staples | 4.7% | 1.3% | +3.4pp |
| Energy | 3.3% | 0.4% | +2.9pp |
| Utilities | 2.2% | 0.3% | +1.9pp |
| Materials | 1.9% | 0.3% | +1.6pp |
Δ is SPYM minus VONG, 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
33.9% of SPYM by weight, held in no part of VONG.
6.4% of VONG by weight, held in no part of SPYM.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| SPYM | VONG | |
|---|---|---|
| Top 10 holdings | 36.7% | 54.3% |
| Positions held | 507 | 370 |
| Cost per $10,000 held, per year | $2 | $6 |
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 SPYM and VONG overlap?
SPYM and VONG overlap 54.8% by portfolio weight — substantial duplication if you hold both. They share 178 holdings. The figure comes from current issuer holdings files (SPYM as of 2026-07-27, VONG as of 2026-06-30).
How is the overlap between SPYM and VONG calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If SPYM holds a stock at 6% and VONG 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 SPYM and VONG?
That depends on your goals — we state facts, not advice. At 54.8% overlap, each fund still contributes meaningfully distinct exposure.
What does SPYM own that VONG doesn't?
SPYM holds 507 positions and VONG holds 370; 328 of SPYM's positions don't appear in VONG at all, and they are 33.9% of SPYM by weight.
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Related comparisons
Sources: issuer holdings files, SPYM as of 2026-07-27, VONG as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.