Wall Street had its worst day since April 2025 on Thursday, 5 November 2026, as a sell-off in AI chip and data-centre stocks spread to the wider market. The Nasdaq Composite fell 5.5% and the S&P 500 fell 4.4%, and the damage carried into Asia on Friday. The trigger was a mix of political worry, weak company guidance and growing doubts about the cost of the AI build-out.
The numbers
- The S&P 500 closed down 4.36% at 7,353.73, according to IBTimes, and the Dow Jones Industrial Average fell 1,833 points, or 3.4%, wiping out the previous day's election-related gains.
- The Nasdaq Composite fell 5.52% and closed in correction territory, 11.9% below its all-time high from last month.
- NBC News reported that the Nasdaq 100 dropped 6.3%, erasing about $2.3 trillion in market value, while the S&P 500 lost about $2.8 trillion.
- Nvidia fell 9.3%, losing almost $450 billion in market value and erasing its gains for the year. AMD fell 17.3%, Micron about 17%, SanDisk about 22% and CoreWeave 9.8%.
- The Philadelphia Semiconductor Index fell about 12%, its worst day since March 2020.
- Not everything fell. AppLovin jumped 31% after strong results and a buyback approval.
What analysts point to
CNBC said chipmakers fell after this week's midterm results raised concerns that the AI build-out could slow, and that Qualcomm's disappointing forecast added to the selling, with the company falling more than 9%. Market commentators linked the sell-off to expectations that a Democratic-controlled Congress could bring closer scrutiny of AI and data-centre development, as we reported on Thursday. Share Talk and Saxo's market notes also cite the rising cost of financing new data centres and doubts about whether future AI revenues will justify the spending. Nvidia's shares have fallen about 15% over the past three months, according to NBC News.
Global fallout
The sell-off extended to Europe and Asia. ASML fell 6.6% and French chipmaker Soitec 16.7%, while Europe held up better because of its lower exposure to AI stocks. In Asia on Friday, South Korea's Kospi dropped by almost 9% at the open, triggering a 20-minute trading halt, according to CNN, after a 5.3% fall the day before. Investors also moved into government bonds. Saxo strategist Charu Chanana cautioned that closer scrutiny of infrastructure expansion does not mean the end of the AI boom or of US ambitions to lead in the technology.
What to watch
- Nvidia reports quarterly results on 17 November, a key test of demand.
- Whether the new Congress, which takes office in January, proposes specific rules on data centres or AI, which would turn expectations into facts.
- The cost of borrowing for AI projects, after this week's bond sales and the roughly $3.2 trillion in off-balance-sheet commitments reported by Nikkei.
Why it matters
One bad day does not decide the future of AI, and previous sell-offs have reversed. But the size of the move shows how much of the market's value now rests on expectations about AI infrastructure. For businesses and governments elsewhere, including in Africa, that depend on cloud services and chips from these companies, the questions are whether financing for new data centres stays available and what that does to prices and supply. This article is a news report and not investment advice.
Sources: CNBC, CNN, NBC News, CBC, IBTimes, Saxo, ChartMill, Share Talk, Kingy AI (all 5–6 November 2026).
