W.026Chip stocks had their worst day since March 2020. Memory makers fell about twice as far as Nvidia
The PHLX Semiconductor Index fell 12.25% on November 5, its worst day since March 2020, as investors sold AI infrastructure stocks after the US midterm elections. SanDisk fell 22.3%, Micron 17.5% and Lam Research 16.4%; Nvidia fell 9.3%, about $447B of market value on its share count. The index closed 38% below its June record. Taiwan’s market fell 4.5% the next day, and Korea’s main index hit a circuit breaker.
What fell, and by how much
The chip index had its worst day in more than six years. The PHLX Semiconductor Index closed at 9,011.14 on Thursday, down 12.25% from Wednesday. Benzinga described it as the worst day since March 16, 2020, and CNN as the worst in about six and a half years; CNT Trading called it the second-worst on record, a ranking 06.ai could not check against the index’s full history. The Nasdaq Composite fell 5.52% and the S&P 500 4.36%. CNN reported that about $2.5 trillion of market value was wiped from the Nasdaq Composite. Coverage tied the selling to the midterm results, including governors-elect who back pauses on new data centers, and to Qualcomm’s weak results the night before.
The suppliers fell further than the chip designer at the center of the build-out. Memory makers SanDisk and Micron fell 22.3% and 17.5%. Lam Research, which sells wafer fabrication equipment, fell 16.4%, and Applied Materials 13.6%, according to CNT Trading. AMD fell 17.3% and Marvell 16.4%. Nvidia fell 9.3%. Micron’s fall was 1.9 times Nvidia’s in percentage terms. The hardest-hit stocks had also risen most this year: Yahoo Finance reported during Thursday’s session that Micron was still up about 148% for 2026 and AMD about 101%, while Nvidia’s close left it below where it ended 2025, CNT Trading reported.
Memory and equipment led the fall
Closing share price change on Thursday, November 5, 2026, % on Wednesday’s close, grouped by what each company sells. Nvidia is drawn in black. Applied Materials’ move is from CNT Trading, and Arm’s and Intel’s from StockTitan, each the only source found; the others agree across at least two.
Three companies lost about $742B of value in a day
Market value lost on November 5, $ billions: the fall in each company’s share price times its shares outstanding in its latest SEC filing (our calculation). The label gives the value at Thursday’s close.
Data
| Company | Close | Change | Prior close, implied | Shares | Value lost |
|---|---|---|---|---|---|
| Nvidia | $181.60 | −9.26% | $200.13 | 24.100B | $447B |
| Micron | $656.39 | −17.46% | $795.24 | 1.131B | $157B |
| AMD | $404.40 | −17.26% | $488.76 | 1.640B | $138B |
Asia followed on Friday
Seoul and Taipei sold off in turn. Korea’s Kospi had already fallen 5.28% on Thursday, with SK hynix down 9.46% and Samsung 7.57%, according to the Korea Times. On Friday morning the index fell 8.52% to 4,924.61 within minutes of the open, triggering a circuit breaker, Korea JoongAng Daily reported. Taiwan’s Taiex closed down 4.51% on Friday at 39,701.64, Focus Taiwan reported, after an intraday fall it called the largest in points in the market’s history.
The memory makers say their orders have not changed. Samsung and SK hynix said chip demand still exceeds what they can supply, and industry sources told Seoul Economic Daily on Friday that customers had not cancelled supply contracts or cut volumes. The paper cited a Modo Energy estimate that about 11 GW of new US data center construction could be halted if governors-elect follow through, about 10 GW of it in Texas, but that the net cut to US capacity would be about 3 GW by 2030 if projects move to other states. 06.ai could not find Modo’s report itself.
The chip index fell nearly three times as much as the S&P 500
Daily change in each index, %: US indexes on Thursday, November 5; Korea’s Kospi at its Thursday close; Taiwan’s Taiex at its Friday, November 6 close, the first session after the US fall.
What this changes on 06.ai
- Pack lead (AI memory balance): memory makers fell furthest on the selloff while saying their orders are unchanged; their fourth-quarter guidance will show whether any customer cuts followed the election.
- Pack lead (Will AI compute run short or long through 2030?): Modo’s estimate, about 11 GW of US construction at risk but about 3 GW of net capacity by 2030, is a dated figure for the demand side if the report itself can be found.
- Watch: Nvidia reports on November 17, the first results from a large AI chipmaker since the election.
Sources and method
| Item | Figure | Source |
|---|---|---|
| SOX | Closed at 9,011.14 on Nov 5, down 1,257.51 points (−12.25%); Nov 4 close 10,268.65 | Yahoo Finance live blog, Nov 5; Nasdaq index page |
| SOX | Index fell 12.3%, its worst day since March 16, 2020; SOXX ETF −12.8%; Lam −16.4%, its worst session since March 2020 | Benzinga, via Webull, Nov 5 |
| SOX | “Second-worst day on record”; SanDisk −22.3%, Lam −16.4%, Applied Materials −13.6%, Nebius −14.9%; Nvidia now −2.6% for the year; Nvidia results Nov 17 | CNT Trading, Nov 6 |
| SOX record | Closing record of 14,634.72 on June 22, 2026 | KuCoin, Jul 30; date also in Yahoo Finance, Jul 8 |
| Closes | Micron −17.46% to $656.39, AMD −17.26% to $404.40, Marvell −16.43%, Arm −13.08%, Broadcom −10.43%, Intel −10.33%, Qualcomm −9.49%, Nvidia −9.26% to $181.60, CoreWeave −9.83% | StockTitan market close, Nov 5 |
| Closes | SanDisk −22.26%; S&P 500 7,353.73, −4.36%; Nasdaq Composite 24,315.00, −5.52%; tech sector −8.00% | CappNotes, Nov 5 |
| Closes | Nebius −14.94%, CoreWeave −9.83% | The Wall Street Republic, Nov 5 |
| Nasdaq | About $2.5 trillion of market value wiped from the Nasdaq Composite; Nasdaq 100 −6.36% | CNN, via KSL, Nov 5 |
| Shares | Nvidia: 24.1 billion shares outstanding as of Aug 21, 2026 | Nvidia 10-Q, quarter to Jul 26 |
| Shares | Micron: 1,131,423,212 shares as of Oct 2, 2026 | Micron 10-K, via StockTitan |
| Shares | AMD: 1,640,087,251 shares as of Oct 28, 2026 | AMD 10-Q, quarter to Sep 26 |
| Year to date | During the Nov 5 session, AMD still up about 101% for the year and Micron about 148% | Yahoo Finance, Nov 5 |
| Seoul | Kospi closed at 5,383.80 on Nov 5, −5.28%; SK hynix −9.46%, Samsung −7.57% | Korea Times, Nov 5 |
| Seoul | Kospi fell 8.52% to 4,924.61 at 9:03 a.m. on Nov 6, triggering a circuit breaker | Korea JoongAng Daily, Nov 6 |
| Taipei | Taiex closed at 39,701.64 on Nov 6, down 1,873.08 points (−4.51%) | Focus Taiwan, Nov 6 |
| Taipei | Taiex fell a record 3,737.67 points intraday, the largest intraday point decline in the market’s history | Focus Taiwan, Nov 6 |
| Lam | Lam Research −16.36% at the close | CappNotes, Nov 5 |
| Chipmakers | Samsung and SK hynix say demand still exceeds supply; industry sources say customers have not cancelled contracts or cut volumes; Modo Energy estimates about 11 GW of new US construction could be halted, about 10 GW of it in Texas, and a net reduction of about 3 GW by 2030 if projects move | Seoul Economic Daily, Nov 6 |
Index: 9,011.14 ÷ 10,268.65 − 1 = −12.25%; 9,011.14 ÷ 14,634.72 − 1 = −38.4%.
Value lost: the prior close is the Thursday close ÷ (1 + the change); the loss is (prior close − close) × shares outstanding. Nvidia: $181.60 ÷ 0.9074 = $200.13; ($200.13 − $181.60) × 24,100,000,000 = $447B. Micron: $656.39 ÷ 0.8254 = $795.24; ($795.24 − $656.39) × 1,131,423,212 = $157B. AMD: $404.40 ÷ 0.8274 = $488.76; ($488.76 − $404.40) × 1,640,087,251 = $138B. Total $742B. Share counts are as of the dates in each filing, not November 5, so the figures are approximate. Ratio: 17.46 ÷ 9.26 = 1.89.
Moves are closing changes as reported; where sources differed (Nvidia’s close was also reported as −8.91% at $182.29 by one roundup), the figure two sources agree on is used.
Wire reports are written within hours of the news, on a six-hour schedule. Each lists its sources and shows the arithmetic behind its figures. Not investment advice.