Samsung and SK Hynix Shares Slide Despite Massive $1.3 Trillion Semiconductor Investment Pledges
South Korean tech giants Samsung Electronics and SK Hynix both announced sweeping chip investment strategies on Monday during a high-profile presidential briefing held in Seoul. Despite the scale of these commitments, investors responded with selling rather than optimism, sending both stocks significantly lower by the end of the trading session.
Samsung Electronics saw its share price drop 5.3%, closing at 321,500 won compared to Friday's close of 339,500 won. SK Hynix fared slightly better but still declined 3.4%, ending the day at 2,583,000 won, down from 2,673,000 won. The broader KOSPI index also retreated, settling around 8,258 after opening near 8,411.
Both Samsung Group and SK Group each presented investment frameworks worth approximately 1,000 trillion won to President Lee Jae-myung. The plans encompass the construction of new semiconductor manufacturing facilities, development of AI-focused data centers, and the buildout of chip industry clusters over the coming decade. When combined, the two pledges amount to roughly $1.3 trillion, as reported by Fortune.
Yet financial markets remained unmoved by the headlines. A significant contributing factor was the Korea Exchange's decision to cancel the planned rollout of weekly options contracts linked to Samsung, SK Hynix, Hyundai Motor, and LG Energy Solution. Regulators pulled the plug on the new product following a surge of retail investor activity in daily double-leveraged ETFs, which drove KOSPI volatility to unprecedented levels. The cancellation effectively eliminated a key instrument used by short-term traders, dampening speculative interest across the board.
The KOSPI has also struggled recently on a broader timeline. While the index posted solid gains over the past twelve months, it has declined over the past month and started the new trading week in negative territory once again.
Sentiment across global tech markets remained fragile. South Korean exchanges triggered circuit breakers on two separate occasions last week amid mounting concerns over inflated AI chip valuations. Given that Samsung and SK Hynix together account for approximately 42% of the KOSPI's total market capitalization, any widespread chip sector selloff hits South Korean markets disproportionately hard. Retail investors who took on significant leverage during recent market rallies are now facing compounding losses as prices continue to retreat.
According to market data shared on social media, the KOSPI closed one of its worst weeks of 2026, shedding roughly 10% in a single week and erasing approximately 550 trillion won — equivalent to around $350 billion — from total market value. AI and semiconductor stocks led the decline as panic selling spread throughout Korean equity markets.
Geopolitical developments added further uncertainty to an already tense environment. Over the weekend, the United States conducted strikes on Iranian military targets, rattling investor confidence across Asia. Tensions eased somewhat after both parties agreed to suspend hostilities and schedule talks in Doha on Tuesday. Meanwhile, Japan's Nikkei 225 also fell, dragged down by a retreat in SoftBank shares following six consecutive sessions of record highs.
