DIA vs VOO: how much do they really overlap?
DIA (SPDR Dow Jones Industrial Average ETF, tracking the Dow Jones Industrial Average) and VOO (Vanguard S&P 500 ETF, tracking the S&P 500) overlap by roughly 35% by weight. 7 of DIA's top 10 holdings also appear in VOO. A 50/50 blend of the two behaves like about 42 equally-weighted bets (diversification grade B). In short, the two funds share a meaningful core of the same megacaps, but each also brings real exposure the other lacks.
The same companies, in both funds
These 16 holdings appear in both DIA and VOO. The weight columns show how much of each fund each name represents.
| Holding | in DIA | in VOO |
|---|---|---|
| MSFT Microsoft Corporation | 4.20% | 5.14% |
| GOOGL Alphabet Inc. | 4.03% | 3.41% |
| AAPL Apple Inc. | 3.21% | 7.05% |
| AMZN Amazon.com, Inc. | 2.73% | 4.07% |
| NVDA NVIDIA Corporation | 2.22% | 7.89% |
| JPM JPMorgan Chase & Co. | 3.75% | 1.16% |
| JNJ Johnson & Johnson | 2.94% | 0.84% |
| V Visa Inc. | 3.89% | 0.83% |
| CAT Caterpillar Inc. | 11.76% | 0.63% |
| UNH UnitedHealth Group Incorporated | 4.78% | 0.53% |
| CVX Chevron Corporation | 1.92% | 0.53% |
| PG The Procter & Gamble Company | 1.69% | 0.51% |
| HD The Home Depot, Inc. | 3.99% | 0.49% |
| GS The Goldman Sachs Group, Inc. | 11.61% | 0.45% |
| MRK Merck & Co., Inc. | 1.47% | 0.45% |
+ 1 more shared holdings.
Only in DIA
SPDR Dow Jones Industrial Average ETF — US blue-chip (Dow 30). Its biggest holdings that VOO doesn’t have:
| AMGN Amgen Inc. | 4.10% |
| SHW The Sherwin-Williams Company | 3.92% |
| AXP American Express Company | 3.88% |
| TRV The Travelers Companies, Inc. | 3.78% |
| MCD McDonald's Corporation | 3.04% |
| HON Honeywell International Inc. | 2.59% |
| BA The Boeing Company | 2.44% |
| MMM 3M Company | 1.85% |
Only in VOO
Vanguard S&P 500 ETF — US large-cap. Its biggest holdings that DIA doesn’t have:
| AVGO Broadcom Inc. | 3.26% |
| GOOG Alphabet Inc. Class C | 2.71% |
| META Facebook Inc. Class A | 2.13% |
| TSLA Tesla Inc. | 1.89% |
| MU Micron Technology Inc. | 1.68% |
| LLY Eli Lilly & Co. | 1.35% |
| BRK.B Berkshire Hathaway Inc. Class B | 1.34% |
| AMD Advanced Micro Devices Inc. | 1.29% |
So — partly overlapping. Should you hold both?
DIA and VOO share a meaningful core of the same megacaps, but each also brings real exposure the other lacks. Held together they keep a shared megacap core but each still pulls in exposure the other lacks, so a 50/50 blend spreads to ~42 effective positions (grade B).
Holdings as of — DIA: Jun 29, 2026 (State Street Global Advisors); VOO: 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 →DIA vs VOO — FAQ
- How much do DIA and VOO overlap?
- DIA and VOO overlap by approximately 35% measured by portfolio weight — that is the share of the smaller fund's holdings (by weight) that also sit inside the other. 7 of DIA's 10 largest holdings are also held by VOO. They share 16 of their listed top holdings in total.
- Is it redundant to hold both DIA and VOO?
- Because they share a meaningful core of the same megacaps, but each also brings real exposure the other lacks, holding both is partly redundant: you double up on a shared core (MSFT) while each fund still adds distinct exposure. A 50/50 blend has an effective 42 positions and a B diversification grade.
- What does VOO hold that DIA doesn't?
- VOO's largest holdings that DIA doesn't hold include AVGO, GOOG, META, TSLA, MU. Its category is US large-cap, versus DIA's US blue-chip (Dow 30).
- Which is more concentrated, DIA or VOO?
- DIA's top 10 holdings are 59% of its listed weight; VOO's are 61%. The more concentrated fund leans harder on its largest names.