SOXX vs VO: how much do they really overlap?
SOXX (iShares Semiconductor ETF, tracking the NYSE Semiconductor) and VO (Vanguard Mid-Cap ETF, tracking the CRSP US Mid Cap) overlap by roughly 6% by weight. 1 of SOXX's top 10 holdings also appear in VO. A 50/50 blend of the two behaves like about 75 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 3 holdings appear in both SOXX and VO. The weight columns show how much of each fund each name represents.
| Holding | in SOXX | in VO |
|---|---|---|
| MRVL MARVELL TECHNOLOGY INC | 4.88% | 0.89% |
| MPWR MONOLITHIC POWER SYSTEMS INC | 2.93% | 0.72% |
| TER TERADYNE INC | 3.36% | 0.58% |
Only in SOXX
iShares Semiconductor ETF — semiconductors. Its biggest holdings that VO doesn’t have:
| MU MICRON TECHNOLOGY INC | 8.54% |
| AMD ADVANCED MICRO DEVICES INC | 8.09% |
| NVDA NVIDIA CORP | 6.81% |
| INTC INTEL CORPORATION | 6.33% |
| AVGO BROADCOM INC | 6.08% |
| AMAT APPLIED MATERIAL INC | 5.77% |
| KLAC KLA CORP | 5.64% |
| LRCX LAM RESEARCH CORP | 4.89% |
Only in VO
Vanguard Mid-Cap ETF — US mid-cap. Its biggest holdings that SOXX doesn’t have:
| STX Seagate Technology Holdings plc | 1.90% |
| WDC Western Digital Corp. | 1.78% |
| VRT Vertiv Holdings Co. Class A | 1.18% |
| PWR Quanta Services Inc. | 1.06% |
| HWM Howmet Aerospace Inc. | 1.03% |
| CMI Cummins Inc. | 0.89% |
| CEG Constellation Energy Corp. | 0.88% |
| SLB Schlumberger Ltd. | 0.81% |
So — essentially different. Should you hold both?
SOXX 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 ~75 effective positions (grade A), because they hold largely different securities.
Holdings as of — SOXX: Jun 30, 2026 (iShares (BlackRock)); VO: 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 →SOXX vs VO — FAQ
- How much do SOXX and VO overlap?
- SOXX and VO overlap by approximately 6% measured by portfolio weight — that is the share of the smaller fund's holdings (by weight) that also sit inside the other. 1 of SOXX's 10 largest holdings are also held by VO. They share 3 of their listed top holdings in total.
- Is it redundant to hold both SOXX 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 75 positions and a A diversification grade.
- What does VO hold that SOXX doesn't?
- VO's largest holdings that SOXX doesn't hold include STX, WDC, VRT, PWR, HWM. Its category is US mid-cap, versus SOXX's semiconductors.
- Which is more concentrated, SOXX or VO?
- SOXX's top 10 holdings are 61% of its listed weight; VO's are 31%. The more concentrated fund leans harder on its largest names.