Key points
- Kospi rebounds 2.46% by 10 a.m.
- SK Hynix and Samsung lead the gains
- Foreign investors buy Samsung, sell SK Hynix
South Korea's Kospi rose 2.46% to 5,689.46 at 10 a.m. Korea time on Wednesday, October 21, recovering more than half of Tuesday's losses. SK Hynix and Samsung Electronics led the rebound after AI server maker Super Micro Computer (SMCI) estimated quarterly revenue well above its earlier forecast. The update helped ease concerns about returns on AI investment, Seoul Economic Daily (서울경제) reported.
The index opened 2.05% higher at 5,666.34. Despite the rebound, it remained about 19% below its October 2 close of 7,003.74, by our calculations.
Tuesday's 3.73% decline took the Kospi to 5,552.74, slightly below its close after the 7.57% selloff on October 15. Foreign and institutional investors were net sellers as concerns about AI financing and investment returns weighed on chip stocks, Digital Daily (디지털데일리) reported.
Meta Platforms (META) reports third-quarter results after Wednesday's US market close, early Thursday morning in Seoul.
SK Hynix and Samsung led the rise
SK Hynix (000660) was up 5.64% at 1,292,000 won ($975) at 10 a.m. Samsung Electronics (005930) was up 4.49% at 221,000 won ($167). On Tuesday, SK Hynix fell 4.23% and Samsung fell 2.98%.
The rise followed a much higher revenue estimate from Super Micro Computer. After the US close on Tuesday, the company said its revenue for the July-to-September quarter was likely between $18.5 billion and $19.5 billion. Its earlier forecast was $14.5 billion to $15.5 billion, and the company credited "increased demand for AI platforms." Supermicro's stock rose more than 13% in after-hours trading.
Lower oil prices and interest rates helped too. Han Ji-young, a researcher at Kiwoom Securities (키움증권), said the market was winning back Tuesday's losses as buyers came in after the fall, as oil and interest-rate pressure eased, and as US chip stocks rose after hours on Supermicro's results, Hankyung (한국경제) reported. Brent crude closed at $108.79 a barrel overnight. During the day it came close to $112, its highest in five months.
Foreign investors are split on the two chipmakers
Foreign investors bought a net 64.8 billion won ($48.9M) of Kospi shares by 9:18 a.m., after selling on Tuesday. Individuals and institutions were net sellers in that time.
Foreigners aren't treating Samsung and SK Hynix the same way. They sold Samsung for 12 trading days in a row, then bought it for three straight days starting October 16, about 850 billion won ($641M) in total. They've sold SK Hynix for 18 trading days in a row. Foreign buying will need to improve for the rebound to last, according to the same report.
Meanwhile, the Kosdaq was up 1.17% at 791.10 at 10 a.m., after briefly climbing back above 800.
Prices and trading flows are timestamped in the text. Won figures are converted at 1,325.8 won to the dollar, the Yahoo Finance rate at 10 a.m. Korea time on October 21, 2026.
