Samsung and SK Hynix Shares Crash 14% Amid Kospi Semiconductor Selloff

The South Korean equity market faced a massive downturn as semiconductor giants Samsung Electronics and SK Hynix witnessed staggering losses of up to 14.5%. This volatility has triggered deep concerns regarding the sustainability of the global AI hardware rally and the potential for overcapacity in the computing sector.

The Catalyst: AI Overcapacity and Meta’s Strategic Shift

The primary driver behind the sudden selloff appears to be reports that Meta Platforms Inc. is considering selling its "excess compute" power. This development has sparked fears among investors that the massive investments in AI infrastructure may have led to an overbuild. Vey-Sern Ling, managing director at Union Bancaire Privee, noted that if tech giants are struggling to find productive uses for their computing power, it has direct negative implications for the "picks and shovels" providers—the semiconductor manufacturers that supply the hardware.

This sentiment was further exacerbated by a massive rout in U.S. technology shares, where major players like Micron Technology Inc and SanDisk both recorded losses exceeding 10% in the previous session.

Volatility Hits the Kospi Index

The impact on the South Korean market was profound, as Samsung Electronics and SK Hynix collectively represent more than half of the Kospi index. As their stock prices plummeted—SK Hynix by over 14% and Samsung by more than 10%—the benchmark Kospi index crashed by 8.2%.

The intensity of the selling pressure was so high that the Korea Exchange was forced to halt trading for 20 minutes after market circuit breakers were triggered. This level of volatility highlights the market's extreme sensitivity to shifts in the AI narrative.

Valuation Concerns and Competitive Pressures

Before this crash, the semiconductor sector showed clear signs of overheating. SK Hynix had seen a meteoric rise of nearly 223%, while Samsung Electronics had gained 123%. Many market participants believe these valuations had moved significantly beyond underlying fundamentals, leaving the sector vulnerable to a correction.

Adding to the pressure is the emerging competitive landscape. Reports that Apple Inc. is in discussions to source chips from two Chinese semiconductor manufacturers have intensified fears that Samsung and SK Hynix may face heightened competition in the global supply chain, potentially squeezing their market dominance.

Resilience Amidst the Correction

Despite this two-day "bloodbath," it is important to note the broader context of the South Korean market. The Kospi remains the world's best-performing major stock index in 2026, having advanced 77% so far this year. The surge has been largely driven by the indispensable role Korean firms play in providing high-bandwidth memory chips required for advanced AI models. However, the current crash underscores a structural vulnerability: the Kospi's heavy reliance on a few semiconductor heavyweights makes the entire index susceptible to abrupt changes in AI sentiment.

Key Takeaways

  • AI Sentiment Shift: Reports of Meta potentially selling excess computing power have triggered fears of AI capacity oversupply, hurting semiconductor stocks.
  • Market Impact: The heavy weightage of Samsung and SK Hynix caused the Kospi to drop 8.2%, necessitating a 20-minute circuit breaker halt.
  • Valuation Correction: The selloff follows a period of extreme growth, with SK Hynix surging 223% and Samsung 123% earlier this year, leading to concerns over overvalued fundamentals.