What happened in the U.S. stock market
November 5, 2026: The sharp decline in AI-related stocks and the impact of the U.S. midterm elections
On November 5, 2026, a significant decline occurred in the U.S. stock market.
Selling was particularly concentrated in companies related to semiconductors and data centers necessary for artificial intelligence development.
The previous day, the stock market had risen sharply following the results of the U.S. midterm elections.
However, the situation changed completely the following day.
This time, we will organize what actually happened in the U.S. market based on reports from Reuters and other news outlets.
We will focus on confirmed events and market reactions, without including future stock price forecasts or personal speculation.
Table of Contents
1. The significant decline in the U.S. stock market
2 Selling concentrated in semiconductor-related companies
3 The decline spread to data center-related companies as well
4 Political changes that occurred in the U.S. midterm elections
5 Why data centers became a political issue
6 What happened in the stock market after the election
7 Impact on markets outside the U.S.
8 Differences between declining companies and rising companies
9 What was confirmed by this event
1 Significant decline in the U.S. stock market
On November 5, major U.S. stock indices saw a significant decline.
The Nasdaq Composite Index fell by 4.9 percent.
The S&P 500, a representative US stock index, fell by 3.2 percent.
The Dow Jones Industrial Average also dropped by 1,079 dollars.
What is particularly noteworthy is that the US stock market had risen significantly the previous day, November 4th.
On that day, the Dow Jones Industrial Average had risen by 1,569 dollars.
However, a significant decline occurred the very next day.
This means the market sentiment changed drastically in just one day.
2 Selling concentrated on semiconductor-related companies
Semiconductor-related companies were particularly prominent in this decline.
Nvidia’s stock price fell by 6.3 percent.
AMD fell by 13.1 percent.
Qualcomm also saw a significant decline.
For Qualcomm, the fact that its sales outlook for smartphone semiconductors fell short of market expectations also became a factor for selling.
In other words, not all semiconductor companies fell for the same reason.
In addition to caution regarding AI-related investments, the earnings and sales outlooks of individual companies also impacted stock prices.
Semiconductors are essential products for the development and operation of artificial intelligence.
Therefore, when the market’s assessment of AI-related capital investment changes, it also affects the stock prices of semiconductor companies.
In this market, that impact manifested as an actual decline in stock prices.
3 The decline also spread to data center-related companies
It was not just semiconductor companies that were sold off.
The decline also spread to companies that operate data centers for artificial intelligence and those that provide computing power.
CoreWeave’s stock price fell by approximately 10 percent.
Related companies such as Nebius, IREN, Hut 8, and Applied Digital were also sold off.
Selling also spread to companies that provide power equipment and related hardware for data centers.
These companies share a common trait.
They all rely on the assumption that the construction of large-scale data centers and the expansion of facilities will continue as artificial intelligence becomes more widespread.
A notable feature of this decline is that it spread not only to companies developing artificial intelligence but also to those providing the equipment and services that support that development.
4. Political Changes Following the U.S. Midterm Elections
On November 3rd, the U.S. held its midterm elections.
In this election, the Democratic Party secured a majority in both the Senate and the House of Representatives.
The political landscape shifted from the situation where the Republican Party had controlled both the House and the Senate.
Of particular note were the election results in regions where data center development is progressing, such as Texas and Georgia.
Reuters reported that investors are wary of the possibility that the Democratic Party’s victory could lead to increased oversight and regulation of data center development.
However, this did not mean that data center construction was banned across the entire United States at this point.
What actually occurred was a change in political power due to the election and the market’s reaction to it.
5 Why did data centers become a political issue?
A massive amount of computational processing is required to run artificial intelligence.
Data centers are what support that computational processing.
In recent years, the construction of data centers for artificial intelligence has been rapidly advancing in the United States.
However, voices of opposition from local residents have also been raised against that expansion.
The issues at hand include massive power consumption, water resource usage, and the impact on local electricity rates.
The benefits that data center construction brings to the local economy, versus the costs borne by residents and the environmental impact, have become political points of contention.
Amidst this situation, movements calling for construction moratoriums or stricter regulations are spreading.
According to a financial institution’s analysis cited by Reuters, it is estimated that approximately 30 percent of the U.S. data center capacity expansion planned for 2028 could be affected by construction moratoriums or similar measures.
However, this does not mean that 30 percent of construction will actually be canceled.
It is a figure that estimates the impact of future regulations.
6 What happened in the stock market after the election
On November 4, the U.S. stock market rose significantly.
The easing of political uncertainty following the Democratic Party’s election victory was reported as a factor in the market’s rise.
However, not all artificial intelligence-related companies rose in the market that day.
While large companies like Amazon, Meta, and Alphabet rose, some data center operators saw their stock prices fall.
In other words, differences in stock price movements between companies were already emerging immediately after the election.
Then, on November 5, selling pressure expanded, centered on semiconductor companies and data center-related firms.
Reuters reported that in addition to concerns over stricter regulations on AI infrastructure following a Democratic victory, investors are also questioning whether massive capital expenditures will generate sufficient profits.
Caution regarding AI-related stocks did not begin suddenly with this election.
In fact, the Nasdaq 100 index had already entered a correction phase by November 2, falling more than 10 percent from its recent high.
It has also been confirmed that stock prices were already declining before the election.
7 Impact on markets outside the U.S.
The stock market decline on November 5 did not occur only in the United States.
South Korea’s benchmark KOSPI index fell by 5.3 percent.
Japan’s Nikkei Stock Average also fell by 1.8 percent.
Artificial intelligence and semiconductor-related companies do not operate solely within the United States.
Companies from many countries, including Japan and South Korea, are involved in the manufacturing of semiconductors and the supply of related components.
In this market, as selling pressure on US artificial intelligence-related stocks intensified, declines were also observed in major Asian stock markets.
Additionally, separate from the stock market, crude oil prices also rose.
Brent crude, the international benchmark for oil prices, rose by 2.5 percent to $96.95 per barrel.
Uncertainty surrounding the war involving Iran was a factor in the crude oil market.
8 The Difference Between Declining and Rising Companies
In this US stock market, many artificial intelligence-related companies saw their share prices fall.
However, not all companies were sold off.
For example, AppLovin, an app advertising-related company, rose by 31.8 percent.
Tapestry, a fashion-related company, also rose by 8.3 percent.
For these companies, earnings and profit outlooks served as catalysts for the stock price increases.
In other words, the market on November 5th did not see all companies decline in the same way.
While companies related to artificial intelligence semiconductors and capital investment were sold off heavily, companies that announced strong earnings saw buying interest.
It can be confirmed that significant differences in stock price movements emerged depending on the companies’ business activities and performance.
9 What was confirmed by this event
On November 5, 2026, the US stock market experienced a significant decline, centered on artificial intelligence-related companies.
The Nasdaq Composite Index fell by 4.9 percent, and the S&P 500 fell by 3.2 percent.
Selling spread not only to semiconductor companies like Nvidia and AMD, but also to data center operators and companies providing related equipment.
The background reported for this includes political changes due to the U.S. midterm elections and market caution regarding massive capital expenditures in artificial intelligence.
However, it cannot be concluded that this decline was caused solely by the Democratic Party’s election victory.
Multiple factors, such as the individual performance of semiconductor companies, interest rates, and crude oil prices, were being simultaneously considered by the market.
Furthermore, the figure that exactly $2 trillion was lost from the U.S. stock market and the claim that this was the fastest market capitalization loss in history are not sufficiently supported by the documents reviewed this time.
What has become clear is the fact that investor valuations of AI-related companies have fluctuated significantly, and the impact has spread beyond semiconductors and data centers to stock markets outside the U.S.
This is not an event indicating that the technology of artificial intelligence itself has declined.
Nor does it indicate that a total collapse of the artificial intelligence-related market is certain.
The fact that can be confirmed at this time is that the stock prices of companies that have grown on the back of massive capital investment have fallen significantly, and the market is strictly evaluating their growth potential and profitability.
This article was created based on reports from November 4 to 5, 2026.
This article does not recommend the purchase or sale of any specific financial products.
Please make final investment decisions at your own risk.