Kospi loses 3.52%, erasing Wednesday's rebound in broad stock selloff
Key Facts
South Korea's Kospi closed Thursday, October 22, 2026, down 201.89 points, or 3.52%, at 5533.77, according to the Seoul Shinmun newspaper, wiping out all the gains from the previous session's rebound. The index had ended Wednesday up 3.29% at 5735.66, according to Investing.com data, before the selloff pushed it back into losses. That rebound followed a 3.73% decline on Tuesday, when the index closed at 5552.74. The Kospi thus ended Thursday below Tuesday's close as well, falling below the level from which the recovery had begun. Losses gave way to gains and then losses again over consecutive sessions, as Wednesday's rally failed to withstand the following day's decline.
The selloff swept across most stocks on the Kospi market, with Seoul Shinmun counting 709 decliners during Thursday's session. By contrast, 174 stocks rose and 32 were unchanged, leaving decliners outnumbering advancers by a wide margin. Among major chip stocks, Samsung Electronics ended the session down 4.03%, according to the newspaper. SK Hynix posted a larger loss of 5.49%, falling more sharply than Samsung and the benchmark index. Both stocks declined more than the Kospi as selling spread to hundreds of other shares in the South Korean market.
Also in the chip sector, Lam Research said in its earnings release on Wednesday that revenue for the quarter ended in September totalled $8.22 billion. That represented a 22% increase from the previous quarter ended in June, according to the results table published by the company. Adjusted diluted earnings per share, calculated on a non-GAAP basis, were $2.20 for the September quarter. The company reported an adjusted operating margin of 40.2% for the same period, alongside its quarterly revenue growth. But Lam Research shares fell in after-hours trading on Wednesday following the earnings announcement, according to Investing.com. The stock dropped 6.25% to $244.50, a market reaction that came despite the reported increase in revenue from the previous quarter.
Lam Research's results also showed the Korean market's presence in its business, with Korea accounting for 20% of September-quarter revenue. China's share was larger, at 35% of revenue for the same period, according to the geographical breakdown in the release. The Chinese market's contribution to the company's revenue thus exceeded that of the Korean market during the quarter whose results were announced on Wednesday. On liquidity, cash, cash equivalents and restricted cash totalled $7.45 billion at the end of the September quarter. Lam Research also disclosed deferred revenue of $2.66 billion at the end of the same period among the financial figures accompanying its quarterly results.
For the December 2026 quarter, Lam Research forecast revenue of $8.60 billion, plus or minus $400 million, according to its release. The midpoint of that guidance exceeds September-quarter revenue, but Chief Financial Officer Doug Bettinger said revenue guidance would have been higher without near-term supply chain constraints. Bettinger cited "some near-term supply chain constraints" when explaining what had limited the guidance, according to the earnings call transcript published by Investing.com. He also linked his expectation of a decline in China business during the December quarter to domestic Chinese customers, saying it would be "driven by domestic customers in China". For the next earnings date of one of the Korean chipmakers mentioned, SK Hynix said it would present its third-quarter results on October 28, 2026. The company scheduled the earnings release for before 9:00 a.m. Seoul time that day.