SPY vs VB: how much do they really overlap?
SPY (SPDR S&P 500 ETF Trust, tracking the S&P 500) and VB (Vanguard Small-Cap ETF, tracking the CRSP US Small Cap) overlap by roughly 0% by weight. 0 of SPY's top 10 holdings also appear in VB. A 50/50 blend of the two behaves like about 215 equally-weighted bets (diversification grade A). In short, the two funds hold almost none of the same securities — they are complementary, not redundant.
The same companies, in both funds
These 0 holdings appear in both SPY and VB. The weight columns show how much of each fund each name represents.
| Holding | in SPY | in VB |
|---|
Only in SPY
SPDR S&P 500 ETF Trust — US large-cap. Its biggest holdings that VB doesn’t have:
| NVDA NVIDIA Corporation | 7.38% |
| AAPL Apple Inc. | 6.47% |
| MSFT Microsoft Corporation | 4.28% |
| AMZN Amazon.com, Inc. | 3.68% |
| GOOGL Alphabet Inc. | 3.24% |
| AVGO Broadcom Inc. | 2.76% |
| GOOG Alphabet Inc. | 2.60% |
| MU Micron Technology, Inc. | 2.02% |
Only in VB
Vanguard Small-Cap ETF — US small-cap. Its biggest holdings that SPY doesn’t have:
| FLEX Flex Ltd. | 0.69% |
| ALAB Astera Labs Inc. | 0.62% |
| CIEN Ciena Corp. | 0.51% |
| RKLB Rocket Lab Corp. | 0.50% |
| CRDO Credo Technology Group Holding Ltd. | 0.48% |
| BE Bloom Energy Corp. Class A | 0.47% |
| EME EMCOR Group Inc. | 0.46% |
| JBL Jabil Inc. | 0.45% |
So — essentially different. Should you hold both?
SPY and VB hold almost none of the same securities — they are complementary, not redundant. Held together they genuinely broaden your exposure — a 50/50 blend reaches ~215 effective positions (grade A), because they hold largely different securities.
Holdings as of — SPY: Jun 29, 2026 (State Street Global Advisors); VB: May 31, 2026 (Vanguard). Refreshed monthly. Overlap is measured across each fund’s largest holdings (top 50); the diffuse long tail barely moves the math.
See this for YOUR whole portfolio, free →SPY vs VB — FAQ
- How much do SPY and VB overlap?
- SPY and VB overlap by approximately 0% measured by portfolio weight — that is the share of the smaller fund's holdings (by weight) that also sit inside the other. 0 of SPY's 10 largest holdings are also held by VB. They share 0 of their listed top holdings in total.
- Is it redundant to hold both SPY and VB?
- Because they hold almost none of the same securities — they are complementary, not redundant, holding both is not redundant — each fund covers largely different holdings, so together they broaden your exposure. A 50/50 blend has an effective 215 positions and a A diversification grade.
- What does VB hold that SPY doesn't?
- VB's largest holdings that SPY doesn't hold include FLEX, ALAB, CIEN, RKLB, CRDO. Its category is US small-cap, versus SPY's US large-cap.
- Which is more concentrated, SPY or VB?
- SPY's top 10 holdings are 71% of its listed weight; VB's are 29%. The more concentrated fund leans harder on its largest names.