Semiconductor stocks swung sharply in the first week of November 2026: according to Investing.com data, the PHLX Semiconductor Index (SOX) rose 2.63% on November 3 as chip stocks rebounded ahead of AMD's quarterly results, then fell 3.13% on November 4 after the US midterm results raised fears that new policies could slow data center construction. It matters for US-stock investors because chipmakers have been key beneficiaries of the AI build-out.
The Driver: SOX Slides From 13,217.8 as AI Spending Doubts Meet Midterm Policy Risk
The pressure built over several weeks. Per Investing.com, the SOX closed at 13,217.8 on October 6, its highest close in the October and November data, and at 10,268.7 on November 4. As of November 3, Yahoo Finance calculated that chip and memory stocks had lost about $3.7 trillion in market value since October 6, as concerns over AI spending and the debt of neocloud companies (cloud providers that rent out AI computing capacity) weighed on the sector.
| Date (2026) | SOX close | Daily change |
|---|
| October 6 | 13,217.8 | +0.34% |
| October 30 | 10,688.8 | -7.20% |
| November 2 | 10,328.3 | -3.37% |
| November 3 | 10,600.4 | +2.63% |
| November 4 | 10,268.7 | -3.13% |
SOX closing levels per Investing.com.
On November 3, investors moved back into key tech names. As reported by CNBC, AMD gained more than 3% ahead of its third-quarter results, Broadcom rose 3%, and Micron and Nvidia each added more than 2%.
Shawn Snyder of Potomac Fund Management told CNBC that "the concerns about the cost of capital and the level of debt financing necessary" persist. The Motley Fool noted that data centers had been a key campaign theme going into the vote.
The next day, the election turned the story to policy. According to CNBC, Democrats won both the House and the Senate, and Gina Hinojosa's lead over Texas Governor Greg Abbott added to the selloff because she has pledged "an immediate moratorium" on data centers.
CNBC cited Wells Fargo estimates that Texas holds about 27% of US data center gigawatts. The SOX fell 3.13% that day, per Investing.com, even as CNBC reported the Dow's roughly 1,500-point gain was its best day since April 2025.
Why Data Center Policy Reaches Chipmakers' Revenue
Data centers are where AI chips end up, so the policy debate goes straight to the sector's demand. AMD's numbers show the scale: according to the company's third-quarter results filed with the SEC, its Data Center segment posted record revenue of $8.5 billion, up 97% year over year, out of total revenue of $13.4 billion.
Investors feared that restrictions on data center construction would reduce AI infrastructure spending, CNBC reported, and memory makers were pressured as that uncertainty spread to memory chip demand, per BigGo Finance.
Not everyone read the selloff as an earnings problem. HSBC chief investment officer Willem Sels told CNBC, "I don't think this is a concern about current earnings because current earnings are strong," attributing the decline mostly to a "mismatch between current spending and future revenues" from data centers. On the other side of the debate, CNBC cited a Gartner analysis that AI revenue will be insufficient to support profitable returns on planned AI capital spending from 2027 to 2030.
AMD, Nvidia and Micron: How the Companies in the Story Are Exposed
AMD sat at the center of the week. Per its SEC filing, third-quarter revenue rose 45% year over year to $13.4 billion, and the company said Data Center growth came from strong demand for its EPYC processors and the launch of its Instinct MI450 Series GPUs.
CEO Lisa Su said, "Demand for our Instinct and EPYC products continued to strengthen," and AMD guided fourth-quarter revenue to about $17 billion, plus or minus 3%. As reported by CNBC, adjusted earnings of $2.09 per share beat the $1.95 estimate, and the shares rose 7% after hours on November 3.
Nvidia's moves tracked the sector. Nvidia shares added more than 2% on November 3 and fell about 3% on November 4, according to CNBC, and Yahoo Finance noted that Nvidia had lost the most market value in dollar terms among chip and memory stocks since October 6.
Memory makers swung the hardest. Per Yahoo Finance, Micron fell 7% on November 2 and recovered 2% on November 3, and BigGo Finance reported a further 7% drop on November 4, with SanDisk and Western Digital also down more than 6%.
What to Watch Next: Nvidia Results on November 17 and Texas Data Center Policy
- Nvidia will host its conference call on Tuesday, November 17, at 2 p.m. PT (5 p.m. ET) for its fiscal 2027 third quarter, which ended October 25, 2026, according to Nvidia.
- CoreWeave, whose roughly 41% fall over the past month CNBC tied to concerns about AI financing, was slated to report earnings after the bell the following Tuesday, CNBC reported on November 3.
- Whether the Texas moratorium pledge becomes policy, in a state that Wells Fargo estimates holds about 27% of US data center gigawatts.
This article is for education and information only and is not investment advice. Investment decisions are your own after doing your own research.
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