U.S. stocks tumbled Thursday as a sharp selloff in semiconductor and artificial intelligence-related companies reversed much of Wall Street’s post-election rally. The Nasdaq Composite fell nearly 4% during morning trading as investors reassessed the outlook for AI infrastructure spending following the 2026 midterm elections.
The technology-heavy Nasdaq declined approximately 3.8%, while the S&P 500 dropped 2.1% and the Dow Jones Industrial Average fell about 1%. The Philadelphia Semiconductor Index plunged more than 9%, reflecting widespread selling pressure across companies involved in AI chips, memory, and data-center infrastructure.
The downturn came just one day after U.S. stocks rallied following Tuesday’s midterm elections. Wednesday’s gains reflected optimism surrounding the new political landscape, but that sentiment quickly faded as investors evaluated potential challenges facing the artificial intelligence industry.
Semiconductor companies experienced some of Thursday’s steepest declines. Nvidia (NVDA) fell approximately 7%, while Micron Technology (MU) dropped around 12%. Advanced Micro Devices (AMD), Qualcomm (QCOM), and other chipmakers also faced substantial selling pressure.
The declines extended to AI infrastructure providers, including CoreWeave (CRWV) and Nebius Group (NBIS), as concerns intensified over the pace and sustainability of data-center expansion.
Investors are increasingly focused on whether additional regulatory scrutiny, permitting requirements, and infrastructure constraints could delay large-scale data-center projects. Concerns surrounding electricity consumption, water usage, and environmental impacts have already created opposition to new facilities in several communities.
According to Reuters, UBS strategists warned that potential delays could affect approximately 30% of data-center capacity additions expected in 2028.
Such disruptions could have significant implications for semiconductor manufacturers that have benefited from billions of dollars in AI infrastructure spending. Companies supplying processors, memory, electrical equipment, and cooling systems depend heavily on continued investment in computing capacity.
The selloff also reflects broader questions about the profitability of artificial intelligence investments. Major technology companies have committed substantial capital to expanding AI capabilities, but investors are increasingly questioning how quickly those investments will generate sufficient returns.
Qualcomm added to the semiconductor industry’s weakness after issuing a disappointing outlook for smartphone-related chip sales, raising additional concerns about demand across the technology sector.
For small-cap investors, the implications extend beyond major chipmakers.
Smaller businesses involved in data-center construction, power generation, specialized cooling, and computing infrastructure have benefited from AI expansion. However, these companies may face heightened risks if major technology customers delay projects or reduce capital expenditures.
Smaller companies often have fewer financial resources to absorb unexpected changes in demand, making them particularly sensitive to shifts in infrastructure spending and borrowing costs.
The broader market decline also comes amid uncertainty surrounding Federal Reserve policy and economic growth. Wednesday’s ADP employment report showed that private employers added 86,000 jobs in October, suggesting continued labor market resilience despite uneven hiring.
Investors are now awaiting Friday’s government employment report for additional insight into the economy and potential interest-rate decisions.
While Thursday’s selloff highlights growing concerns about AI infrastructure investment, it does not necessarily signal an end to the industry’s long-term growth.
For Wall Street, the central question is whether the decline represents a temporary reassessment of technology valuations or the beginning of a broader shift away from companies most exposed to the AI investment cycle.
As markets digest the election results and upcoming economic data, semiconductor stocks and AI infrastructure companies will remain important indicators of investor confidence heading into 2027.
