What Is SK Hynix? The Little-Known Tech Giant That Just Knocked Samsung Off Its Throne

SK Hynix has pulled off one of the most striking reversals in South Korean corporate history. On Monday, the chipmaker overtook Samsung Electronics to become South Korea's most valuable listed company, ending Samsung's long run at the top that had stretched back to 2000.

The moment was more than a stock market milestone. It marked the arrival of SK Hynix as the dominant force in one of the most important corners of the artificial intelligence race.

Once a debt-ridden company that nearly collapsed and spent years under creditor control, SK Hynix is now the world's most valuable memory chipmaker and a major supplier of the high-bandwidth memory chips that power AI systems for customers, including Nvidia and Google.

Its rise has been fuelled by the global rush into AI, a sharp rally in its shares, and a well-timed bet on a specialised type of memory chip that has changed the economics of the semiconductor business.

How AI Memory Chips Changed the Race with Samsung

The company's rise to the top has been driven by its strength in high-bandwidth memory, or HBM, a type of chip that has become central to the AI boom. These chips are reportedly used in AI systems and are designed to deliver faster performance with lower power consumption by stacking memory vertically. That has made them very different from traditional memory products, which were often treated as interchangeable commodities.

On Monday, SK Hynix shares closed up 5.6%, taking its market capitalisation to 2,080.4 trillion won, or roughly £1.1 trillion. Samsung, whose stock slipped 0.14%, ended with a market value of 2,066.7 trillion won, or about £1.09 trillion, excluding preferred shares.

Samsung pushed back on the comparison, saying its preferred shares should also be counted. Including those shares, Samsung said its market value stood at 2,246.4 trillion won, which works out to around £1.18 trillion.

Still, the market move underlined how much AI has reshaped the semiconductor industry. SK Hynix focuses mainly on memory chips, while Samsung's business stretches across logic chips and consumer electronics such as smartphones and televisions.

As demand for AI infrastructure has exploded, memory chips tailored for those systems have become far more valuable than the commodity products that once defined the sector.

Kim Sunwoo, a senior analyst at Meritz Securities, said, 'The emergence of customised AI memory fundamentally changed the industry's economics and allowed SK Hynix to establish itself as the market leader.'

That shift has shown up in SK Hynix's financial performance as well. The company suffered heavily during the memory downturn in 2023, reporting an annual operating loss of 7.73 trillion won. But as spending from companies such as Microsoft, Google, and Meta accelerated with the AI boom, SK Hynix bounced back hard. In 2024, it reported an annual operating profit of 23.5 trillion won, a record at the time.

How SK Hynix Rose Into the HBM Market

SK Hynix's current position is especially striking given where it stood two decades ago. In 2002, then known as Hynix Semiconductor, the company was close to being sold to Micron after being crushed by debt built up during an aggressive expansion push.

That deal eventually collapsed, and Hynix spent nearly a decade under creditor control. In 2003, its shares fell as low as 135 won, leaving it seen as a penny stock, or 'Dongjeon-ju' in Korean.

Its recovery has not simply been about better market conditions. Analysts have pointed to one decision in particular: SK Hynix kept investing in HBM during a downturn in the memory market, even when the wider industry was under pressure.

That choice has now given it a commanding position in a part of the chip business that is harder to enter and offers suppliers more pricing power because the chips are tightly linked to AI processors.

By 2025, SK Hynix had captured 61% of the global HBM market, according to the figures cited by analysts. Samsung was on 17%, while Micron held 21%. That lead has helped turn SK Hynix into a core supplier in the AI ecosystem and put pressure on Samsung's standing in memory as well.

SK Hynix was founded in 1983 as a unit of Hyundai before later being spun off and acquired by SK Group, the family-run conglomerate whose businesses range from telecoms to energy. SK Group Chairman Chey Tae-won said in a book published in January that the aim of acquiring Hynix was to move it away from being a commodity memory producer and into a position where its products were indispensable.

'What I really wanted to accomplish when we acquired Hynix was to transform it from a commodity memory producer into a mainstream semiconductor company whose products are indispensable,' Chey said.

He added: 'In the past, it did not matter whether memory came from Hynix, Samsung, or Micron. They were interchangeable commodity products. HBM is different. If SK Hynix's HBM is replaced with another product, the AI system may not function properly. What used to be a peripheral component has become a core component.'

Analysts now believe Samsung's position as the world's largest DRAM producer could also face a challenge. Bank of America estimates SK Hynix's monthly DRAM output will reach about 589,000 wafers this year, compared with roughly 691,000 for Samsung.

But SK Hynix is expected to expand DRAM output by about 38% between 2025 and 2028, against around 17.5% growth for Samsung. That would cut the production gap to less than 10% by 2028, down from around 23% in 2025.

Further reports say that SK Hynix is choosing Nasdaq for a planned US listing, a move that would give it greater visibility with international investors and add another chapter to one of the most dramatic turnarounds in the global chip industry.