The KOSPI plunged as much as 4.3% on overnight US chip weakness before Samsung Electronics and SK Hynix powered an afternoon reversal, closing up 0.68% at 6,742.74. Foreign investors sold heavily into the dip while retail bought. Nvidia’s earnings loom Wednesday.
Samsung Electronics’ record 110 trillion won shareholder-return plan fell short of market hopes, sending the stock down 8.7% and the KOSPI below 6,700. Rotation money lifted the KOSDAQ 1.4% as batteries and biotech rallied.
Seoul’s two markets went opposite ways: KOSPI recovered from a 1.35% opening drop to close up 0.88%, while KOSDAQ fell 4.63% and tripped its 32nd sidecar trading curb of 2026 as rising US yields hammered growth stocks.
The KOSPI jumped 5.89% to 6,852.58 after SK Hynix unveiled a record 40 trillion won buyback-and-cancellation plan. Foreign investors bought 1.7 trillion won of Seoul shares while the won hit its strongest level against the dollar in about 11 months.
Korea’s KOSPI closed down 5.80% at 6,471.17 after a US Treasury yield spike and a global semiconductor rout hit Samsung Electronics and SK Hynix. A sell-side sidecar fired at the open, retail investors bought the dip, and the won broke below 1,400.
The KOSPI surged past 7,200 intraday on a semiconductor rally, then an afternoon wave of profit-taking erased the entire gain, closing down 1.55% at 6,869.83. Foreign investors kept buying while locals sold, and the collapse of the US-Iran ceasefire added a fresh layer of risk.
The KOSPI rose 2.42% to 6,977.94 — a fifth straight gain — after briefly crossing 7,000. Foreign investors bought roughly 1.45 trillion won of KOSPI shares, concentrated in Samsung Electronics and SK Hynix, while soft US inflation data supported risk appetite.
The KOSPI closed at 6,813.34, up 3.56% for a fourth straight gain, as an in-line US CPI print and shareholder-return hopes sent foreign investors piling into Samsung Electronics and SK Hynix. The catch: small caps fell and the won weakened.
Korea’s KOSPI closed at 6,579.04, up 3.68%, after Samsung Electronics rose 6.68%, SK hynix gained 5.54%, and futures rose fast enough to trigger a buy-side sidecar. Foreign and institutional buying overwhelmed heavy retail selling, while the KOSDAQ barely recovered from an early drop.
Korea’s customs service publishes preliminary export data on the 1st, 11th and 21st of every month — one of the earliest official readings on global chip demand. Here is what each release contains, why working-day-adjusted daily averages beat the headline YoY number, and how Samsung Electronics and SK hynix trade the print.