A record one‑day drop follows the chipmaker's Wall Street listing as investors book profits
SK Hynix shares closed 15.4 percent lower in Seoul on Monday, the steepest one‑day fall in the South Korean memory chipmaker's history.
According to LSEG data cited by CNBC, the drop came three trading days after the company's Nasdaq debut and erased much of a rally that had more than tripled the stock this year.
SK Hynix raised more than US$26bn last week selling American depositary receipts at US$149 each, Reuters reported.
The receipts opened 14 percent above that price at US$170 and ended their first session at US$168 before the sell‑off spread back to the Seoul listing.
Analysts pointed to profit‑taking and to uncertainty over how to price the US‑listed shares against the Korean stock.
"Everybody's really confused about what's going to happen to the memory demand and where the fair price is," Daniel Yoo, global strategist at Yuanta Securities, told CNBC's Squawk Box Asia.
The decline rippled across the region.
Samsung Electronics fell alongside SK Hynix and helped drive a 9 percent plunge in South Korea's Kospi that triggered a 20‑minute trading halt, Reuters reported.
US‑listed peers also dropped, with Micron Technology down 6.4 percent, SanDisk 8.4 percent and Western Digital 6.8 percent, while the Philadelphia SE Semiconductor Index lost 3.6 percent, according to the wire service.
For investors weighing the two listings, the gap is wide.
After Monday's rout, SK Hynix's ADRs, which each represent one‑tenth of a Seoul share and last traded at US$154.70, sat at a premium of about 25.6 percent to the Korean price.
Yoo told CNBC that Taiwan Semiconductor Manufacturing's US receipts trade at roughly a 13 to 14 percent premium to its home shares, and that SK Hynix's move had opened a gap of more than 20 percent between its two listings.
Some strategists cast the pullback as a pause rather than a turn.
"We've had such a run up in (memory chip) stocks that there's obviously a component of profit taking but I don't think it's the end of the run," said Phil Blancato, president and chief executive of Ladenburg Thalmann Asset Management, in comments to Reuters.
He added that demand looked strong into late 2027 and early 2028.
SK Hynix's chief executive, Kwak Noh‑jung, went further.
"We forecast that next year will be the worst year in the industry's history from the supply perspective," Kwak told Reuters, predicting that customer demand would outstrip the company's output beyond 2030.
Not all analysts share that view.
According to Reuters, Jing Jie Yu, an equity analyst at Morningstar, said new capacity arriving in 2027 and 2028 should ease supply and pull prices lower.
SK Hynix has led the market for high‑bandwidth memory, the chips used in Nvidia and Google AI systems, with a 58 percent revenue share in the first quarter against 21 percent each for Samsung and Micron, Reuters reported, citing Counterpoint Research.
The sell‑off landed during a rough stretch for chip stocks, which have wrestled this month with high valuations and doubts about the durability of AI spending.
Oil rose on Monday after US President Donald Trump said Washington would reinstate a blockade on Iranian ports, and US equities fell.
Christopher Waller, a governor at the US Federal Reserve, added to the pressure, saying the bank might need to raise rates in the near term if inflation held well above its 2 percent target.
The debut is likely to draw other Asian technology firms toward foreign investors, though appetite may prove selective, investors told Reuters.
"SK Hynix is a special case because it is large, liquid, AI‑critical, and hard for many US investors to own directly," said Ophir Gottlieb, chief executive of Capital Market Laboratories.
Japanese memory maker Kioxia has signalled an ADR listing as soon as the second quarter of 2027 and data‑centre operator DayOne is planning a US‑Singapore dual listing targeting a US$20bn valuation.
