ITOT vs VO: how much do they really overlap?
ITOT (iShares Core S&P Total US Stock Market ETF, tracking the S&P Total Market) and VO (Vanguard Mid-Cap ETF, tracking the CRSP US Mid Cap) overlap by roughly 0% by weight. 0 of ITOT's top 10 holdings also appear in VO. 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 ITOT and VO. The weight columns show how much of each fund each name represents.
| Holding | in ITOT | in VO |
|---|
Only in ITOT
iShares Core S&P Total US Stock Market ETF — total US market. Its biggest holdings that VO doesn’t have:
| AAPL APPLE INC | 6.78% |
| NVDA NVIDIA CORP | 6.54% |
| MSFT MICROSOFT CORP | 4.64% |
| AMZN AMAZON.COM INC | 3.19% |
| GOOGL ALPHABET INC CLASS A | 2.71% |
| AVGO BROADCOM INC | 2.54% |
| GOOG ALPHABET INC CLASS C | 2.18% |
| META META PLATFORMS INC CLASS A | 1.64% |
Only in VO
Vanguard Mid-Cap ETF — US mid-cap. Its biggest holdings that ITOT doesn’t have:
| VRT Vertiv Holdings Co. Class A | 1.22% |
| WDC Western Digital Corp. | 1.06% |
| STX Seagate Technology Holdings plc | 1.04% |
| PWR Quanta Services Inc. | 1.04% |
| HWM Howmet Aerospace Inc. | 1.04% |
| CMI Cummins Inc. | 0.95% |
| DDOG Datadog Inc. Class A | 0.83% |
| BE Bloom Energy Corp. Class A | 0.79% |
So — essentially different. Should you hold both?
ITOT and VO 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 — ITOT: Jul 30, 2026 (iShares (BlackRock)); VO: Jun 30, 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 →ITOT vs VO — FAQ
- How much do ITOT and VO overlap?
- ITOT and VO 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 ITOT's 10 largest holdings are also held by VO. They share 0 of their listed top holdings in total.
- Is it redundant to hold both ITOT and VO?
- 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 VO hold that ITOT doesn't?
- VO's largest holdings that ITOT doesn't hold include VRT, WDC, STX, PWR, HWM. Its category is US mid-cap, versus ITOT's total US market.
- Which is more concentrated, ITOT or VO?
- ITOT's top 10 holdings are 59% of its listed weight; VO's are 27%. The more concentrated fund leans harder on its largest names.