Concerns over tighter oversight of AI data center development after the U.S. midterm elections spilled into South Korean equities on Nov. 5, sending the country’s two benchmark indexes into market-stabilization measures in the same session and dragging semiconductor and power-equipment shares sharply lower.
South Korean benchmarks trigger stabilization measures
The Korea Composite Stock Price Index, or KOSPI, opened down 1.82% on Nov. 5 and extended losses through the morning. It later triggered a sell-sidecar mechanism, temporarily halting program-driven sell orders.
As of 2:25 p.m. local time, the KOSPI was down 5.50% from the previous session at 5,371.41, while the KOSDAQ had fallen 5.11% to 678.4. The two indexes rarely trigger market-stability mechanisms on the same trading day. Samsung Electronics and SK Hynix were down 7.8% and 9.81%, respectively.
The report said Samsung Electronics and SK Hynix together account for more than half of KOSPI market capitalization, magnifying the effect of any shift in semiconductor sentiment on the broader benchmark.
Election outcome sharpens worries over data center approvals
The immediate trigger for the sell-off was a rapid rise in concern that approvals for new U.S. data centers could face delays. Democrats won control of both chambers of Congress in the midterm elections and also captured governorships in several states with a high concentration of data centers.
In Texas, governor-elect Gina Hinojosa pledged during the campaign to immediately pause approvals for all new data centers if elected. The Texas Tribune, citing analysis from DataCenterWatch, reported that 43% of 74 gubernatorial candidates across 36 states said they supported pausing or banning new data center construction.
Wall Street’s sector split from the previous trading day added to the pressure. On Nov. 4, the S&P 500 rose 1.58%, the Dow Jones Industrial Average gained 3.03%, and the Nasdaq climbed 1.44%. But the internal picture was uneven.
Apple, Microsoft, and Amazon each rose more than 5% in a single day, while semiconductor names including Nvidia, Micron, SanDisk, and Intel broadly fell, with declines ranging from 3% to 8%.
AI compute-rental companies CoreWeave and Nebius dropped 9.9% and 6.7%, respectively. The Philadelphia Semiconductor Index fell 3.1% to its lowest level in nearly six months.
Chip and power-equipment stocks lead the decline in Seoul
Losses in South Korea were concentrated in semiconductor names and power-equipment companies tied closely to AI infrastructure. Samsung Electronics fell 5.39%, SK Square lost 6.56%, and Samsung Electro-Mechanics dropped 10.31%.
Semiconductor equipment makers listed on the KOSDAQ were also hit hard. Jusung Engineering fell 10.23%, Simmtech dropped 13.90%, and EO Technics lost 11.72%.
Transformer and other power-equipment makers also came under pressure as investors weighed the possibility that delayed data center construction would cut demand for electrical equipment. Hyosung Heavy Industries, HD Hyundai Electric, and Sanil Electric fell 10.10%, 7.53%, and 12.84%, respectively.
Analysts split on how far the impact can go
Seo Sang-young, an analyst at Mirae Asset Securities, said: 「Democrats also won elections in key data center regions such as Texas and Georgia, sharply increasing market concern over tighter regulation on grid access, approval procedures, and electricity costs. Companies that built new data centers with heavy borrowing would face higher financing costs and greater earnings pressure if project schedules are delayed.」
Kim Seok-hwan, a senior researcher at Mirae Asset Securities, said: 「Tighter AI regulation could disrupt capital spending plans at large technology companies. These companies need to build data centers to deliver the computing capacity they promised to clients such as OpenAI and Anthropic, and ultimately convert those commitments into cloud revenue. Delays in data center construction would push back the revenue realization window, prompting hyperscale cloud providers to reassess the pace of future investment, while demand expectations for high-bandwidth memory and other advanced chips would also come under pressure.」
A report from the New York office of the Bank of Korea said the election outcome was unlikely to drive a major shift in the overall policy direction of the Trump administration, but it 「could have a limited effect on AI regulation and the pace of related investment.」
Yang Jun-seok, an economics professor at the Catholic University of Korea, said that even if Democrats control both chambers, they would still struggle to secure the two-thirds majority needed to override a presidential veto. In his view, that fundamentally limits how far policy can move, making it difficult to expect a direct and substantial hit to AI investment from the election result alone.
He added, however, that if Democrats later make a tighter stance on AI development and investment more explicit, the effect could become a 「meaningful additional suppressive factor」 when combined with existing pressures, including public concern over AI replacing jobs, raising energy bills, and consuming large amounts of water, as well as debt pressure on large technology companies that have borrowed heavily to invest in AI.
Jo Yeon-ju, a researcher at NH Investment & Securities, took a more constructive view. She said: 「Democrats also understand the strategic importance of leadership in AI and are unlikely to impose large-scale delays rashly. They are more likely to offer compensation to local residents to move data center projects forward. The real impact on large technology companies may turn out to be a storm in a teacup.」
An analyst at iM Securities also said that while concern over tighter approval rules for AI data centers was weighing on semiconductor investment sentiment, expectations for cost savings from lower oil prices were spreading to sectors such as airlines and transportation.
Renewable energy seen as a relative beneficiary
Even as the broader market came under pressure, some sectors were viewed as potential beneficiaries of the so-called blue wave. With Democrats strengthening their majority, expectations rose that support policies for renewable energy could regain momentum. Solar, wind, nuclear, and energy storage system, or ESS, related stocks were widely cited as likely beneficiaries.
Ahn Joo-won, a researcher at DS Investment Securities, said: 「With Democrats holding stronger bargaining power in future legislation after their overwhelming election victory, demands from renewable energy sectors such as solar and wind are likely to be reflected more fully, and wind power and fuel-cell related stocks stand to benefit.」
Lee Jae-won, a researcher at Yuanta Securities, offered a cautionary note. He said: 「After Democrats took control of Congress and won governorships in key states, the probability of stricter regulation for AI data centers has increased. Approval restrictions and grid-cost pressure in major data center construction regions such as Texas could delay AI capital investment, which in turn may weigh on memory semiconductor demand and selling prices.」
