South Korea’s benchmark KOSPI reversed early gains on Tuesday, slipping back below the 7,000 level as foreign investors continued to sell and the country’s two largest chipmakers weighed heavily on the index. The KOSPI opened 0.58% higher but was down 0.56% at 6,964.85 by late morning in Seoul. Foreign investors dumped a net 737.2 billion won of shares, while institutions bought 141.9 billion won.
Samsung Electronics fell more than 1%, and SK Hynix dropped around 2.66% to 3%, leaving Seoul weaker than several other Asian markets. That decline came despite a supportive external backdrop: the Nasdaq rose 1.05% to a record close overnight, the Dow gained 0.18%, and Japan’s Nikkei 225 added about 0.4%.
The selling is part of a longer trend. Foreign investors unloaded a net 20.3 trillion won of KOSPI shares between September 1 and October 2, with Samsung and SK Hynix accounting for roughly 17.2 trillion won, or about 85% of that total. US 10-year Treasury yields around 5.3%, near the highest since 2002, have also made richly valued technology shares harder to justify.
Goldman Sachs is warning that Samsung faces a rare “triple-hit” volatility event on Thursday, October 8, when the company’s preliminary earnings, semiconductor ETF rebalancing, options expiry, and the end of a stock buyback program all land on the same day. Goldman analyst Heather Oh described the pileup as unusually bumpy for the stock. Goldman estimates Samsung’s third-quarter operating profit at 106 trillion won, close to the street consensus of 105.5 trillion won but about 5% below its previous forecast of 112 trillion won. The estimate cut reflects a stronger Korean won, with the dollar-won rate near 1,418 versus Goldman’s earlier assumption of 1,460.
Mechanical selling is adding pressure. Seven semiconductor ETFs with a combined $14 billion in assets are scheduled to rebalance on October 8, and Samsung is expected to face outflows from weighting caps. Samsung’s 15 trillion won buyback program is also wrapping up, removing a steady source of buying support. Goldman notes foreign investors had sold Samsung shares for five straight days heading into the event, totaling roughly $2.6 billion.
Underlying chip fundamentals remain strong. South Korea’s semiconductor exports surged 262.8% year over year to a record $60.3 billion in September. Goldman expects Samsung’s HBM bit shipments to climb close to 50% quarter-over-quarter, powered by the ramp-up of HBM4 chips. Micron’s recent earnings also reinforced that AI demand should keep memory supplies tight for at least another year. SK Hynix is expected to report its third-quarter results later in October after its blockbuster ADR offering.
