For one day, at least, South Korea had a new most valuable company.
SK hynix, one of the world’s largest producers of memory chips, surpassed Samsung Electronics in market capitalization on Monday. After a 5.6% surge in its share price, SK hynix was worth over 2.1 quadrillion won ($1.35 trillion), just ahead of Samsung at $1.34 trillion.
Samsung retook the top spot on Tuesday, after SK hynix’s shares slumped nearly 12.5% as part of a broad tech sell-off. Samsung’s shares dropped 12.3%, while the KOSPI index also dropped 10%.
Still, SK hynix’s rise to the top is a rapid change for a company that, at one point, was lost in the wilderness as a struggling electronics maker, spun off from Hyundai in 2003 and acquired by SK in 2011.
SK hynix is now the world’s leading producer of high-bandwidth memory (HBM), key to the manufacture of AI processors and graphics processing units made by companies like Nvidia. The company controls about 58% of the HBM market as measured by revenue, according to Counterpoint Research. Samsung and Micron Technologies sit in second and third place, respectively. Samsung, in particular, was slow to enter the AI processor market, letting SK hynix become the exclusive supplier for Nvidia’s Hopper and Blackwell platforms.
The AI boom has lifted SK hynix’s fortunes by a staggering amount. The company generated a record 97 trillion won ($63.1 billion) in revenue in 2025, a 47% jump from the year before and reaching a record for the company. The jump in profits was even more impressive: SK hynix earned 42.9 trillion won ($27.9 billion) in net profit, double the year before.
More broadly, memory chipmakers like SK hynix, Samsung, and Micron are benefiting from a worldwide shortage of memory chips from the rapid build-out of AI infrastructure.
SK hynix’s shares are up by almost 900% over the past 12 months, compared to almost 180% for the broader KOSPI index.
Korean investors have piled into the country’s stock market to try to capture these massive gains. For example, insurance surrender payouts in Korea jumped 16% in the first quarter of the year, according to the Korea Herald citing industry data, as Koreans cashed out their policies in order to dump money into Korean stocks.
Chip workers at both SK hynix and Samsung are expecting hefty bonuses this year, thanks to bumper profits at both chipmakers. An earlier Reuters report estimated that SK hynix workers could get a bonus of 700 million won ($455,000) if the firm earns 250 trillion won in annual profit.
Koreans have even joked about the SK hynix jacket being the “ultimate blind date outfit,” and employees are quickly becoming hot commodities in the dating market. “If SK hynix and Samsung Electronics employees used to be classified as B+ or A-grade candidates, today they are closer to A+,” Son Dong-gyu, chief executive of matchmaking agency Bien Aller, told Reuters.
Still, not everyone is comfortable with the massive investor interest in the Korean chipmakers.
On Monday, Lee Chan-jin, who leads South Korea’s financial regulator, said he regretted letting single-stock leveraged exchange-traded funds tracking SK hynix and Samsung debut earlier this year. “Reflecting on the situation, wondering if I should have laid down to protest the launch by any means necessary to block it then,” he said.
These ETFs are a hit in other markets too. On Tuesday, a leveraged ETF in Hong Kong designed to deliver twice SK hynix’s daily return, hit $16.8 billion in assets, surpassing the Tracker Fund, the city’s oldest ETF which tracks the Hang Seng Index.
According to Bloomberg, the SK hynix ETF is attracting the second-largest level of inflows this year, behind a similar ETF for Samsung Electronics.
U.S. investors will soon get their chance to buy into the SK hynix hype. The chipmaker has filed confidentially for a U.S. listing, and media reports suggest the debut could come as soon as August.