SPY vs VTTHX: 35% overlap
SPDR S&P 500 ETF Trust and Vanguard Target Retirement 2035 share 34.8% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 4 months apart — VTTHX as of 2026-03-31, 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 1.7. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
SPY and VTTHX hold 501 of the same securities. The ten contributing most to the overlap figure:
| Holding | in SPY | in VTTHX | Δ |
|---|---|---|---|
| NVDA | 7.9% | 2.5% | 5.5% |
| AAPL | 7.4% | 2.3% | 5.1% |
| MSFT | 4.4% | 1.5% | 3.0% |
| AMZN | 3.6% | 1.2% | 2.3% |
| GOOGL | 2.9% | 1.1% | 1.8% |
| AVGO | 2.9% | 1.0% | 2.0% |
| GOOG | 2.4% | 0.9% | 1.5% |
| MU | 1.8% | 0.7% | 1.1% |
| META | 2.1% | 0.7% | 1.4% |
| TSLA | 1.4% | 0.6% | 0.8% |
Where SPY and VTTHX 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 | VTTHX | Δ |
|---|---|---|---|
| Information Technology | 37.5% | 19.5% | +18.0pp |
| Unclassified | 0.0% | 11.2% | −11.2pp |
| Treasuries | 0.0% | 11.2% | −11.2pp |
| Communication Services | 9.3% | 4.5% | +4.8pp |
| MBS Pass-Through | 0.0% | 4.7% | −4.7pp |
| Health Care | 9.1% | 5.2% | +3.9pp |
| Corporate — industrial & other | 0.0% | 3.6% | −3.6pp |
| Consumer Discretionary | 8.8% | 5.7% | +3.1pp |
Δ is SPY minus VTTHX, 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
0.1% of SPY by weight, held in no part of VTTHX.
64.9% of VTTHX 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 | VTTHX | |
|---|---|---|
| Top 10 holdings | 36.9% | 26.4% |
| Positions held | 505 | 6 |
| Cost per $10,000 held, per year | $9 | $8 |
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 VTTHX overlap?
SPY and VTTHX overlap 34.8% by portfolio weight — moderate overlap. They share 501 holdings. The figure comes from current issuer holdings files (SPY as of 2026-07-23, VTTHX as of 2026-03-31).
How is the overlap between SPY and VTTHX 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 VTTHX 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 VTTHX?
That depends on your goals — we state facts, not advice. At 34.8% overlap, each fund still contributes meaningfully distinct exposure.
What does SPY own that VTTHX doesn't?
SPY holds 505 positions and VTTHX holds 6; 3 of SPY's positions don't appear in VTTHX at all, and they are 0.1% of SPY by weight.
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Related comparisons
Sources: issuer holdings files, SPY as of 2026-07-23, VTTHX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.