tech · chips

seoul’s memory stocks fall 7% while tsmc’s sales keep climbing

korea’s main index dropped 7.4% as samsung and sk hynix slid on fears about the ai boom and a chinese rival. the same week, tsmc said its sales were up by more than half.

issue no. 3researched and drafted by ai.

  • chips
  • memory
  • markets
  • 7.4%, kospi’s fall on tuesday
  • 8.8%, sk hynix’s fall
  • 54.6%, tsmc’s sales rise, year on year
kospi and share moves from the associated press; tsmc figure from its own monthly report.

by the close on tuesday, korea’s kospi sat at 5,914, the lowest it has been since late july, the associated press reports. in june it was above 9,000. sk hynix fell 8.8% and samsung electronics 7.7%, and because those two make up so much of the index, a bad day for memory chips becomes a bad day for the whole country’s market.

two worries met. one is the old question of whether ai spending can keep growing at this pace. the other is new: reports that china’s cxmt has made progress on memory designs, which would put a new rival in the market samsung, sk hynix and micron share between them. the selling was not about this quarter’s sales; it was about who sells memory in two years.

memory makers

  • samsung down 7.7%, sk hynix down 8.8% in a day
  • a chinese rival claims progress
  • prices swing with every hint of oversupply

the foundry

  • tsmc september sales near nt$512 billion
  • up 54.6% on a year ago, 41.1% so far this year
  • its shares fell only 1.6% on tuesday
the same week, two halves of the chip trade.

tsmc is the useful contrast. as a it builds other people’s designs, including the ai accelerators that memory gets stacked beside, and its own report last week showed september revenue up 54.6% on a year earlier, with only a 0.6% dip from august. demand for the chips themselves has not cracked. what traders priced in on tuesday is the fear that memory, a business famous for boom and bust, is heading for the bust half again.

pick one

tokyo felt it too. which japanese name fell furthest on tuesday?

next to watch: tsmc’s october sales report, which it usually posts around the tenth of the month. a dip there would mean the worry has reached the foundry too. still unknown: how close cxmt really is, since nothing about its claim has been independently tested.

sources

  1. september 2026 revenue report · tsmcprimary
  2. kospi sinks more than 7% on semiconductor sell-off · associated press