SK hynix and Samsung slide 3-5% before Seoul open on U.S. vote

Shares of SK hynix and Samsung Electronics were trading 3% to 5% lower in Seoul’s premarket session on Nov 5, 2026, Seoul Economic Daily reported. No other outlet gave a range for the drop. The newspaper did not give a separate figure for each company.

Seoul Economic Daily linked the slide to the U.S. elections. It said the Democratic Party had swept the vote, and that the result had raised concern that AI data centers could come under regulation. The newspaper did not say what form such rules might take. It also did not say which officials or lawmakers might write them.

Micron slipped first in New York

The same worry had already reached U.S. chip stocks before Seoul opened. In a story posted at 12:17 a.m. Korean time on Nov 5, MarketWatch reported that Micron Technology and other chipmakers had lost ground. The outlet said the election results had undercut the optimism built around data centers. Micron is the U.S. maker of memory chips, the products at the center of SK hynix’s business.

Barron’s had reported the move a few hours earlier, in a piece posted at 10:15 p.m. Korean time on Nov 4. It said Micron’s shares were falling as warnings about memory prices mounted after the Democrats’ strong showing.

The U.S. session ends before Seoul’s trading day begins. That order means overnight moves on Wall Street are often the first thing Korean traders react to; Pacific Tape explains how the four markets’ hours line up.

One stock, close to a quarter of the KOSPI 200

For investors outside Korea, the size of SK hynix is what makes an early slide matter beyond one company. On Nov 4 its market value was about 1,019.8 trillion won. That was 23.54% of the total market value of the KOSPI 200, the index of Korea’s 200 largest listed companies. A drop of several percent in a stock of that weight shows up in any fund that tracks the index.

Foreign money was already flowing out of Korean stocks before the premarket drop. On Nov 4, foreign investors recorded net selling of 2,497.7 billion won (about US$1.862 billion) across all KOSPI shares. That figure covers the whole market, not SK hynix alone. The KOSPI still ended that day at 5,683.8, up 0.62%. Pacific Tape has a guide to how foreign flows move the KOSPI and where the daily data is published.

Strong profit, weaker shares

SK hynix ended the regular session on Nov 4 at 1,396,000 won, a dip of 0.14% from Nov 3. At 1,341.5 won per dollar, that close was worth about US$1,040.63. The stock had lost 6.12% over the five sessions to Nov 4. Over 20 sessions the decline reached 21.26%.

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That slide came even as the company’s results grew sharply. On Oct 28, SK hynix filed a preliminary consolidated operating profit of 83,333.8 billion won (about US$62.1 billion) for the third quarter of 2026. The figure was 37.6% above the second quarter and 632.1% above the same quarter a year earlier. It was the highest operating profit in at least six quarters, as Pacific Tape reported when the results came out.

The figures are the company’s early estimate and may still change in its full quarterly report. Seoul Economic Daily tied the Nov 5 premarket drop to the U.S. vote, not to anything in SK hynix’s own results. Neither company had commented on the election or on any data center rules.

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Information only, not investment advice.