Korean wave: How Samsung and SK Hynix pulled historic 200% rally in Korean markets

The Korean wave is riding all over the world, and now it's not just limited to Korean beauty and drama. The Korean stock markets have become the new favourite “K” thing in the world, due to their explosive rally in the past year. The Korean benchmark index KOSPI has rallied over 130% in the past year after staying stagnant for the past five years. Unlike India, the post-COVID rally in Korea was limited till mid 2021 as the rally fizzled out soon due to weak macro fundamentals. However, during mid 2025, the Korean markets started rallying for an explosive and euphoric rally, which no one anticipated. Here’s what led to the exponential rally.

2024: From memory to digital oil

The AI wave that started in the US has now spread across Korea and Taiwan, as high demand for chips has led to high demand for memory chips. In early 2024, the HBM (High Bandwidth Memory chips) saw a structural shift from being just a component to becoming a major piece of equipment of the AI ecosystem. In March 2024, SK Hynix began mass production of HBM3E (the fifth-generation chip) and became the exclusive supplier for NVIDIA’s H100 and H200 AI GPUs.

By mid-2024, SK Hynix announced that its capacity was fully sold out through 2025. The sharp rise in demand for HBM chips created FOMO amongst global tech giants. Alongside this, Samsung cleared major technical hurdles and started manufacturing 8-layer and 12-layer HBM3E chips. Soon after Samsung’s entry, the Korean memory chip manufacturers opened the floodgates for multi-billion-dollar orders from global tech giants. The memory chip has now become worth digital oil.

To serve the existing orders, Samsung and SK Hynix moved away from traditional PC and smartphone memory chips, which also created an artificial supply shortage for traditional memory chips, leading to a sharp spike in memory chip prices.

The new leaders of the memory chip market

Soon after capturing the major demand from global tech giants, Samsung and SK Hynix became global leaders in the HBM supply chain. The P&L statements of Samsung and SK Hynix swelled owing to a sharp ramp-up in demand, which sold out capacities. SK Hynix revenue jumped from KRW 17.6 trillion in Q1 2025 to KRW 52.6 trillion, and the operating margins swelled from ~42% to ~72% during the same period. SK Hynix's growth was derived from the supply of HBM3E chips to NVIDIA. Meanwhile, Samsung benefited from the supply of HBM4 and 80% jump in traditional memory chip prices.

Samsung’s Q1 2026 revenue jumped from KRW 71.9 trillion to KRW 133.9 trillion. Similarly, the operating margins also jumped from 9% to 43% during the same period. Samsung made a profit equivalent to the entire year of 2025 in one single quarter of Q1 2026. SK Hynix transformed itself from a net-debt company to a net-cash company from early 2025 to Q1 2026.

Pushing the ceiling higher

As the profits swelled and the prospects remained even stronger, investors lined up to participate in the euphoric rally. Samsung Electronics’ share price went up 442% in a year, from KRW 53,800 to KRW 2,91,500 and SK Hynix’s share price soared more than 866% in a single year. The euphoric rally continues to awe investors across the globe. These two memory giants hold more than 53.9% composition in the Korean stock market, pulling the KOSPI index to record highs. Consequently, the KOSPI index jumped nearly 200% during the same period from 2550 to 7,999.