Last updated: October 31, 2026
Semiconductor Index Values and Chip Stock Benchmarks
Thirty companies, one number, and the entire AI buildout priced through it. That is what the SOX is for.
The benchmark, this week
The PHLX Semiconductor Sector Index — SOX to everyone who trades it — is the chip economy's scoreboard: 30 of the largest U.S.-traded companies designing, distributing, manufacturing, and selling semiconductors, capitalization-weighted, run by Nasdaq since its acquisition of the Philadelphia Stock Exchange. It began on December 1, 1993 at a base value of 200.00 and split two-for-one on July 24, 1995. What it measures has changed beyond recognition since — from PC-era chipmakers to the foundries, equipment makers, and accelerator designers that the AI buildout runs on — while the methodology has stayed deliberately boring, which is exactly what a benchmark is supposed to do.
What sits inside the number
The Nasdaq factsheet as of June 30, 2026 shows how concentrated the benchmark has become. NVIDIA alone carries a 10.34% weight, Micron 8.65%, and Broadcom 7.69%; the top ten names together account for well over half the index. Applied Materials (5.84%), KLA (5.71%), Marvell (5.29%), Lam Research (4.95%), ASML (4.49%), Intel (4.43%), and TSMC (4.15%) complete the top ten. That concentration is the trade: SOX is less a diversified sector bet than a leveraged view on a handful of companies' ability to keep converting AI demand into earnings, and its swings — including the factsheet's reported year-to-date return of 101.14% for its period — reflect that leverage in both directions.
| Top 10 components (factsheet, June 30, 2026) | Weight |
|---|---|
| NVIDIA (NVDA) | 10.34% |
| Micron Technology (MU) | 8.65% |
| Broadcom (AVGO) | 7.69% |
| Applied Materials (AMAT) | 5.84% |
| KLA (KLAC) | 5.71% |
| Marvell (MRVL) | 5.29% |
| Lam Research (LRCX) | 4.95% |
| ASML | 4.49% |
| Intel (INTC) | 4.43% |
| TSMC | 4.15% |
Source: Nasdaq SOX factsheet — source
The counterweight to any index enthusiasm is mechanical: SOX rebalances and reconstitutes, capping its largest constituents, so today's weights are a snapshot that the methodology will revise. A benchmark that never changed would stop describing its sector; a benchmark that changes constantly would stop being comparable. SOX threads that needle annually, and the page will track the weights each time the factsheet updates.
Changelog
- October 2026: First edition. Figures compiled from the public sources listed below; trend baselines set where no prior-period figure was published by the same source.
- October 31, 2026: SOX level updated to the Oct 30, 2026 close of 10,688.80 (down 7.20% on the day, down 0.84% vs the Oct 23 staged figure). 1-year return and factsheet weights unchanged — no newer values published.
Sources
- Nasdaq SOX index history page — https://indexes.nasdaqomx.com/index/History/SOX
- Nasdaq SOX factsheet (PDF) — https://indexes.nasdaqomx.com/docs/FS_SOX.pdf