The S&P 500 fell 4.4% on Thursday, erasing about $2.8 trillion, while the Nasdaq 100 dropped 6.3% and the Philadelphia semiconductor index dropped 12.3%, its worst day since March 2020. That evening Trump told savers on Truth Social that “it wasn’t Republicans, it was Dumocrats.” The casualty list says something more specific than that: the stocks that fell hardest had no news of their own, and the two with fresh earnings fell less.
The political explanation has a mechanism behind it, and it deserves a fair statement. Analysts say investors fear a Democratic Congress will regulate AI and slow data-center construction, and many Democratic winners did pledge to do just that, with Texas, Ohio, Michigan and Georgia named as the big data-center markets. Skepticism of the buildout is not a Democratic monopoly, either: in September the House passed a data-center power-cost bill, 417 to 3.
But the blame lands on people who cannot have caused the loss. Democrats take control of Congress in January. Until then Republicans hold both chambers and the White House, and nothing Democrats promised has become law. Fear of a future policy moved prices. Whether that policy ever arrives is a separate question.
So we sorted the casualties in NBC’s rundown by whether it cited any company-specific news.
What the Table Shows
| Stock | Thursday move | Company news cited |
|---|---|---|
| SanDisk | Down 22% | None cited |
| Micron | Down 17% | None cited |
| AMD | Down 17% | None cited |
| Western Digital | Down 17% | None cited |
| Seagate | Down 16% | None cited |
| Arm | Down 13% | Earnings Wednesday night, read as mixed |
| Qualcomm | Down 9.5% | Earnings Wednesday night, read as mixed |
| Nvidia | Down 9.2% | None cited (its biggest one-day fall since April 2025) |
The five memory and chip names with nothing cited fell an average of 17.8% (22, 17, 17, 17 and 16, divided by five). Arm and Qualcomm, which reported Wednesday night, fell an average of 11.3% (13 and 9.5, divided by two). If company news were the story, the order would run the other way.
It does not clear Democrats entirely, because the names hit hardest are the ones that sell into the AI buildout, which is exactly what the new majority has threatened to slow. It does tell you the sort of event this was. Kospi fell more than 8% on Friday and triggered a trading halt, and Taiwan’s index fell 9%, so Korean and Taiwanese chipmakers took the same beating as American ones. That pattern fits a repricing of AI spending, with the election as the occasion.
We think the better reading is Ed Yardeni’s: an AI bubble losing some air very, very rapidly. Trump’s reading is the weaker one. He is assigning a Thursday loss to Democrats who have no power to cause it until January, and his own company did not get a pass from the party line: Trump Media fell nearly 25% on Wednesday, the day the Dow posted its biggest gain of the year, then another 10.5% on Thursday, to about $4.
Friday’s futures were mixed. The Nasdaq composite is still up more than 30% since Election Day 2024. The real test comes in January, when the data-center promises meet a committee calendar. Until then one party holds every lever, and it is not the one Trump is blaming.