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What crashed the stock market Thursday and what happened next

The Nasdaq lost $2.3 trillion in a single session on November 5 after Democrats swept the midterms and investors bet that a new Congress will slow America's AI data-center boom. Here's what actually happened.

On Thursday, November 5, 2026, the U.S. stock market had one of its worst days in years. The Dow fell nearly 1,833 points. The Nasdaq entered correction territory. Roughly $2.3 trillion in market value vanished in a single session. The proximate cause was the 2026 midterm election results: Democrats swept both chambers of Congress and won a string of governor's races, and Wall Street's immediate reaction was to dump everything tied to artificial intelligence and data centers. By Friday morning, some of those losses were clawing back. But the two days together told a story about how fragile the AI trade had become, and how much of the stock market's 2026 gains rested on a single political assumption.

The numbers, plainly stated

The Nasdaq Composite declined 5.52% on Thursday to close at 24,315. The S&P 500 dropped 4.36% to end at 7,353.73, and the Dow Jones Industrial Average shed 1,833 points, or 3.44%, settling at 51,523.06.

On the Nasdaq 100 specifically, the damage was even more concentrated: that index fell more than 6% and lost about $2.3 trillion, a record, while chip stocks fell 12.3% and Nvidia lost over $440 billion in market value.

The Nasdaq suffered its worst session since the tariff shock of April 2025, with AI chip stocks at the center of the selloff. Wall Street headed for its worst post-midterm day since 1896, according to one market tracker.

The S&P 500 dropped 4.36 percent, the Dow Jones Industrial Average lost 3.44 percent, and nearly $3 trillion was erased from the value of S&P 500 companies, according to Yahoo Finance.

What actually triggered it

The midterm results came in Tuesday, November 3. Democrats won the House, the Senate, and key governorships. Markets initially cheered: stocks rallied sharply on Wednesday. Then investors did the math overnight.

Wall Street suffered a sharp selloff on Thursday as concerns over tighter regulation of artificial intelligence infrastructure following Democratic election victories rattled investor confidence. Democratic wins in states where opposition to new data centers has gained momentum raised fears that policy changes could slow the massive AI infrastructure buildout that has fueled this year's stock market rally.

Democrats won both chambers of Congress in the November 3 midterm elections, and traders began pricing in a tougher policy backdrop for AI. Yassamin Ansari, a Democrat, called on November 4 for a pause on advanced AI development until adequate regulations are in place. For AMD and Nvidia, that rhetoric raised the prospect of slower data center buildouts just as both companies were ramping new systems.

The nationwide victories by Democrats raised the possibility that governments could force pauses in construction of more data centers. That is not a hypothetical concern in some states. Public opposition to data center siting has grown over electricity costs, water use, and local land-use fights, and several Democratic candidates ran explicitly on slowing or conditioning new construction.

Chip stocks took the worst of it

After a Democratic sweep of both chambers of Congress, which could spell more regulation of the AI buildout, stocks tied to the AI trade, particularly those linked to the chips industry and data centers, slid for a second consecutive day.

Nvidia sank about 9.26%, while the Philadelphia Semiconductor Index plunged more than 12%. Broadcom fell 10% and Oracle moved lower by almost 7%.

AMD posted the biggest, most profitable quarter in its history, yet its stock was punished harder than any rival. Political risk outweighed strong earnings across the AI chip trade. AMD stock fell 13% in morning trading.

Nvidia fell 6.3% and was by far the heaviest weight on the S&P 500, a day after dropping 3.2%. CoreWeave, a company that rents access to AI chips to customers over the cloud, fell 10%.

Nvidia fell about 9.2% and lost more than $440 billion in value. The stock turned negative for 2026.

Big tech players dipping below their respective 200-day moving averages included Nvidia, Advanced Micro Devices, Marvell Technology, Micron Technology, Sandisk, and Cisco.

Did the stock market actually 'crash'?

That word gets used loosely, and it matters here. A correction is a decline of 10% or more from a recent peak. A bear market is 20% or more. A crash typically implies a sudden, panic-driven plunge that breaks something structural. Thursday was bad, but it did not break anything.

The sell-off inflicted sharp one-day losses, particularly on technology companies, but the broader market remained far short of the threshold commonly used to define a bear market.

As of November 5, 2026, the Nasdaq 100 was 14.7 percent below its record and therefore in a correction; the S&P 500 was 5.9 percent below its record.

As bad as Thursday's stock market washout was, conditions had to get a lot worse before the New York Stock Exchange circuit breakers would kick in and pause trading. Those circuit breakers, which halt trading when the S&P 500 drops 7%, 13%, or 20% intraday, never came close to triggering.

The 2026 market rout erased trillions in value, but the S&P 500 remained well short of losses seen in previous major crashes. A sharp, technology-led stock market rout following the U.S. midterm elections wiped trillions of dollars from American companies, though its scale so far remained well short of the crashes that defined previous financial crises.

So: a severe single-day selloff and a Nasdaq correction, yes. A systemic crash in the 1929 or 2008 sense, no.

Why the AI trade was so exposed

The stock market's gains in 2025 and through most of 2026 were concentrated in a small number of companies. Nvidia, the chipmaker whose graphics processing units power nearly every major AI training cluster, became the second-largest company in the S&P 500 by total market value. That outsized weight had a mechanical effect.

A 1% move for Nvidia has more effect on the S&P 500 than almost every other U.S. stock because it is the second-largest company by total value. That allowed the drops for AI chip stocks to drown out gains for much of the rest of the S&P 500, where a slight majority of stocks actually rose on Thursday.

In other words: most stocks did not crash Thursday. The index crashed because a handful of very large technology and semiconductor companies collapsed together, all for the same political reason.

Investors sold AI infrastructure stocks on fears that a Democratic sweep in the midterms will slow data-center construction and the AI capital-spending cycle. That is distinct from fears about AI demand or the underlying technology. The assumption was not that AI would stop working. It was that the physical infrastructure needed to run it at scale, the data centers, the power contracts, the chip orders, would face new regulatory friction and slower permitting at the state and federal level.

The global spillover

Asian semiconductor stocks tumbled Thursday, as investors weighed the implications of a sweeping Democratic victory in the U.S. midterms.

Stock markets worldwide felt pressure from continued drops for companies in the artificial-intelligence industry, and South Korea's Kospi index tumbled 5.3%. Japan's Nikkei 225 also felt the sting of drops for tech and AI-related stocks, falling 1.8%.

South Korea's market reaction was especially sharp because companies like Samsung and SK Hynix supply memory chips to Nvidia and other U.S. AI hardware makers. Any slowdown in U.S. data center construction hits Asian component makers almost immediately.

Trump's response

President Donald Trump responded by blaming Americans for how they voted in the elections, posting on his Truth Social platform: "The Stock Market crashed today because the Dumocrats had a big Tuesday."

That framing was straightforward political messaging. The market had rallied strongly in 2025 and much of 2026 under a divided government, and Trump wanted to attribute the selloff to the election outcome rather than to the structural concentration in a single trade. Economists and market analysts pointed out that the selloff was specifically tied to AI regulation fears, not to any broad economic policy change that Democrats had announced.

Friday's partial recovery

The day after a historic selloff can go either way. Friday, November 6, went better than many expected.

U.S. stocks staged a partial recovery on November 6, with the Nasdaq Composite climbing 1.73% as Nvidia and other semiconductor companies rebounded following one of Wall Street's steepest technology selloffs in years.

Nvidia gained approximately 5.6%, while the Philadelphia Semiconductor Index rose 4.6% after losing more than 12% in the previous session.

An October jobs report landed at 8:30 a.m. and gave buyers extra confidence. Nonfarm payrolls rose by 165,000 versus the Dow Jones consensus of 59,000, and the unemployment rate ticked down to 4.1% from 4.2% in the prior month. A labor market that strong pushed back against the idea that the economy was softening headed into a new political era.

Chip stocks led the recovery, with a gauge tracking major semiconductor companies jumping 6%, while the Nasdaq 100 gained 2%.

Some analysts cautioned it was too early to trust the rebound and declare Thursday the final washout. The underlying question, what a Democratic Congress will actually do about AI and data centers, remained entirely unanswered.

What Democrats have actually said about AI regulation

The market's reaction was driven by fear of what might happen, not by any specific bill that passed or executive order that was signed. Democrats as a party do not have a single unified position on AI data centers.

Some candidates who won on Tuesday ran on local objections to specific data center projects: noise, power grid strain, water consumption. Others have called for federal safety standards on AI model development. Yassamin Ansari called on November 4 for a pause on advanced AI development until adequate regulations are in place, which is a more sweeping position than most of her colleagues have endorsed publicly.

Investors feared that a Democratic sweep of both chambers of Congress as well as victories in key gubernatorial races could spell more regulation of the AI buildout across the country. Chip and AI infrastructure stocks fell again "including in some key data-center states, where public opposition to the industry's rapid expansion has been growing," Reuters reported.

The distinction matters for investors. State-level siting fights over individual data center projects are real and ongoing. A federal moratorium on AI development is a different category of action entirely, one that would face substantial legal and political obstacles even with Democratic majorities.

What to watch next

Several things will tell investors whether Thursday was a one-day panic or the beginning of a longer repricing of the AI trade.

The near-term outlook depends on three developments: whether semiconductor shares can sustain their recovery, whether Treasury yields stabilize following the employment report, and whether major technology companies maintain their AI investment plans.

Nvidia's next earnings report will be a flashpoint. So will any committee hearings in the new Congress on AI oversight. And the data center permitting fights already in progress in Virginia, Texas, Arizona, and Georgia will serve as early tests of whether Democratic governors and state legislatures actually move to slow construction, or whether the market's fears were overblown.

For everyday investors with index funds, the week's events are a reminder of how much concentration risk has quietly built up inside funds that look diversified. The S&P 500 is not, in practice, 500 equal companies. Five or six of them, all in the same technology sector, now account for a disproportionate share of the index's total weight. When those names move together, the whole index moves with them.

Nasdaq futures rebounded the morning after the tech-heavy index had its worst day in 19 months on post-election concerns about a data center buildout slowdown. As of Friday afternoon, Nvidia sat at roughly $197, still down sharply from its October peak but well off Thursday's low.

Sources