The KOSPI Composite Index reached a record high of 8,457.09 on Wednesday, gaining 2.3% to close at 8,229.70 after rising as much as 5.1% during the session. According to Reuters, the sharp gains triggered a "sidecar" curb that temporarily halted algorithmic trading. The index has delivered exceptional returns of 212.84% over the past year, with year-to-date returns of 94.78% and six-month returns of 105.96%. The 52-week low was 2,643 and today sits around 8,228.70, representing what analysts describe as not normal stock market numbers requiring specific explanation beyond general growth prospects.
South Korean retail investors have collectively poured nearly ₩20 trillion, roughly $13.2 billion, into SK Hynix as the memory chipmaker's market cap crosses $1 trillion. According to latest reports, these local traders have been dubbed "Sam-nix" for their aggressive accumulation of SK Hynix shares. The retail influx has been instrumental in pushing the KOSPI index to record levels, with SK Hynix, alongside Samsung Electronics, now accounting for nearly half of the entire KOSPI index. South Korea's retail trading community comprises roughly 14 million individuals, meaning more than one in four South Koreans is actively trading stocks. This retail enthusiasm has served as a counterweight to foreign investors who have been taking profits on the way up.
SK Hynix topped $1 trillion in market value for the first time on Wednesday, joining its memory chip rivals Samsung Electronics and Micron Technology in reaching this milestone on an AI-driven rally. As reported by Reuters, SK Hynix shares closed 9.3% higher on Wednesday, after rising as much as 14.9% during the session to take the South Korean chipmaker's market value to a record 1,680 trillion won ($1.12 trillion). The company's shares have delivered remarkable 215% returns over the past year, significantly outpacing Samsung's 149% and Micron's 245% gains. Samsung Electronics had previously surpassed $1 trillion in market value for the first time on May 6, while U.S.-listed Micron did so on Tuesday.
Memory chip prices have experienced dramatic increases driven by AI infrastructure demand, with memory chip prices doubling in the first quarter alone from the previous period and forecast to increase by up to 63% in the current quarter due to AI data centre demand. According to Reuters, high-bandwidth memory (HBM) chips now constitute a growing share of SK Hynix's DRAM revenue, as these specialized memory chips are designed to sit next to AI accelerators in data centers, feeding them data fast enough to keep up with massive language models and training workloads. Strong demand for high-end memory chips used in AI chipsets like those designed by Nvidia has tightened supply and driven up prices, benefiting the world's biggest makers of the semiconductors. The company has positioned itself as a primary supplier to major US technology firms including Nvidia, Google, and Microsoft, with analysts predicting the AI memory market cycle could last for several years underpinned by ongoing Big Tech capital expenditure.
SK Hynix reported revenue of approximately 97 trillion won for full-year 2025, with operating profit roughly doubling year-over-year. First quarter 2026 results reinforced the trend, with AI semiconductor sales driving the bulk of the momentum. The company's strong financial performance has been supported by its leadership in HBM technology, which gives it pricing power that commodity chipmakers rarely enjoy. However, the current rally faces headwinds as foreign investors are already booking gains, with retail traders having to absorb $13.2 billion in selling pressure to keep the rally going. The same concentration that drives the rally represents the primary risk embedded in the KOSPI at current levels, with the index pricing a world where AI hardware demand continues to grow at the pace set over the past two years.
