ITOT vs SOXX: how much do they really overlap?
ITOT (iShares Core S&P Total US Stock Market ETF, tracking the S&P Total Market) and SOXX (iShares Semiconductor ETF, tracking the NYSE Semiconductor) overlap by roughly 25% by weight. 3 of ITOT's top 10 holdings also appear in SOXX. A 50/50 blend of the two behaves like about 45 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 9 holdings appear in both ITOT and SOXX. The weight columns show how much of each fund each name represents.
| Holding | in ITOT | in SOXX |
|---|---|---|
| NVDA NVIDIA CORP | 6.54% | 8.42% |
| AVGO BROADCOM INC | 2.54% | 7.91% |
| MU MICRON TECHNOLOGY INC | 1.36% | 8.21% |
| AMD ADVANCED MICRO DEVICES INC | 1.09% | 8.57% |
| INTC INTEL CORPORATION | 0.60% | 5.24% |
| AMAT APPLIED MATERIAL INC | 0.55% | 5.08% |
| LRCX LAM RESEARCH CORP | 0.51% | 4.27% |
| TXN TEXAS INSTRUMENT INC | 0.35% | 4.16% |
| KLAC KLA CORP | 0.33% | 4.28% |
Only in ITOT
iShares Core S&P Total US Stock Market ETF — total US market. Its biggest holdings that SOXX doesn’t have:
| AAPL APPLE INC | 6.78% |
| MSFT MICROSOFT CORP | 4.64% |
| AMZN AMAZON.COM INC | 3.19% |
| GOOGL ALPHABET INC CLASS A | 2.71% |
| GOOG ALPHABET INC CLASS C | 2.18% |
| META META PLATFORMS INC CLASS A | 1.64% |
| JPM JPMORGAN CHASE & CO | 1.30% |
| BRKB BERKSHIRE HATHAWAY INC CLASS B | 1.30% |
Only in SOXX
iShares Semiconductor ETF — semiconductors. Its biggest holdings that ITOT doesn’t have:
| TSM TAIWAN SEMICONDUCTOR MANUFACTURING | 4.57% |
| MRVL MARVELL TECHNOLOGY INC | 4.08% |
| ADI ANALOG DEVICES INC | 4.04% |
| MPWR MONOLITHIC POWER SYSTEMS INC | 3.54% |
| NXPI NXP SEMICONDUCTORS NV | 3.48% |
| TER TERADYNE INC | 3.22% |
| QCOM QUALCOMM INC | 2.75% |
| ASML ASML HOLDING ADR REPRESENTING NV | 2.43% |
So — partly overlapping. Should you hold both?
ITOT and SOXX 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 ~45 effective positions (grade B).
Holdings as of — ITOT: Jul 30, 2026 (iShares (BlackRock)); SOXX: Jul 30, 2026 (iShares (BlackRock)). 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 SOXX — FAQ
- How much do ITOT and SOXX overlap?
- ITOT and SOXX overlap by approximately 25% measured by portfolio weight — that is the share of the smaller fund's holdings (by weight) that also sit inside the other. 3 of ITOT's 10 largest holdings are also held by SOXX. They share 9 of their listed top holdings in total.
- Is it redundant to hold both ITOT and SOXX?
- 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 (NVDA) while each fund still adds distinct exposure. A 50/50 blend has an effective 45 positions and a B diversification grade.
- What does SOXX hold that ITOT doesn't?
- SOXX's largest holdings that ITOT doesn't hold include TSM, MRVL, ADI, MPWR, NXPI. Its category is semiconductors, versus ITOT's total US market.
- Which is more concentrated, ITOT or SOXX?
- ITOT's top 10 holdings are 59% of its listed weight; SOXX's are 61%. The more concentrated fund leans harder on its largest names.