South Korea's stock market is in the grip of a retail investor frenzy drawing comparisons to past speculative bubbles. The benchmark Kospi index has surged more than 200% over the past year, minting new millionaires while pushing margin debt to all-time highs — and few seem willing to ask how long it can last.
The Kospi closed at a record high of 7,981.41 on May 14, up 1.75% on the day, cementing South Korea's position as the world's seventh-largest equity market by total capitalization, now valued at roughly $4.6 trillion. The rally has been driven largely by explosive demand for artificial intelligence infrastructure, which has turbocharged profits at memory chipmakers Samsung Electronics and SK Hynix — both central to the global AI supply chain.
A Once-in-a-Lifetime Trade — or So Retail Investors Believe
The market euphoria has spread well beyond trading floors. Conversations about stock gains now dominate offices, family gatherings, and social media feeds across the country, fueling a fear-of-missing-out dynamic that analysts say has reached an unusual intensity.
Data from Toss Securities show that the number of new brokerage accounts opened by investors under the age of 18 surged nearly tenfold in the first quarter of this year compared with the same period a year earlier — a sign that parents are increasingly buying stocks on behalf of their children.
Jang Eunjung, a 37-year-old YouTuber who runs a popular investment channel, said retail sentiment has moved beyond enthusiasm into something closer to mania. Her subscriber count has ballooned to more than 1.3 million. "Will we ever see a vertical rally like this again?" she asked.
Wall Street Lifts Targets — Some as High as 10,000
The AI boom has been a direct catalyst. SK Hynix reported profits more than five times higher year-on-year in its most recent quarter, driven by soaring memory prices and surging demand for high-bandwidth memory chips used in AI servers. Samsung Electronics' market capitalization recently crossed $1 trillion, making it Asia's second-largest company by that measure after Taiwan Semiconductor Manufacturing Co.
Several Wall Street institutions have raised their Kospi price targets in recent weeks, with the most optimistic scenarios projecting levels of 9,000 or even above 10,000 points.
Yet signs of excess are mounting alongside the optimism.
A $300 Billion Flash Crash and a Government Tax Scare
Earlier this week, the Kospi shed roughly $300 billion in market value in less than two hours after a senior government official suggested on Facebook that authorities might tax windfall AI profits to fund a universal "citizen dividend." The comment triggered an immediate selloff on fears of increased taxation on technology companies.
Officials subsequently clarified that the post reflected a personal view rather than formal policy, and the market partially recovered. But the episode illustrated how fragile sentiment has become — and how quickly an offhand remark can spark a cascade of selling when valuations are stretched and nerves are taut.
Leverage at Record Highs
Retail investors are not just buying stocks — many are borrowing heavily to do so. Data from the Korea Financial Investment Association show that margin lending balances hit a record 36.3 trillion won (approximately $26 billion) in early May, a 32% increase from the end of last year. Analysts warn the true figure may be higher still, as some leveraged purchases are financed through loan categories not captured in official statistics.
Jaewon Choi, an economics professor at Seoul National University, said the speculative surge reflects a broader loss of confidence in conventional paths to wealth. "More and more people believe that working a regular job is no longer enough to change their financial circumstances," he said. "High-risk assets like stocks and cryptocurrencies are increasingly seen as the only viable route to rapid wealth." After years of cryptocurrency-driven wealth stories, he added, much of that speculative energy is now flowing into AI-linked equities such as SK Hynix.
The phenomenon is not unique to South Korea. In Taiwan — another linchpin of the global AI supply chain — Storm Media has previously reported that rising equity markets have prompted a growing number of households to divert savings originally earmarked for property purchases into stocks, betting on further capital gains.
Who Holds the Last Ticket?
The question preoccupying more cautious market participants is not whether the rally will end, but who will be left holding losses when it does.
Kim Taewhan, a physician who suffered heavy losses during the 2018 Bitcoin crash, drew a direct parallel to the current environment. "The real danger is that investors keep adding to their positions in the final stages of a rally, and then take the biggest hit when the correction comes," he said. "That's exactly what I did — I doubled down when the market was at its most euphoric, and ended up losing money."
Kyle Lee, a day trader who sold his Korean equity positions earlier this year and shifted into Nasdaq futures, said he recognizes the pull of FOMO but has grown increasingly reluctant to chase the rally. "I think when a correction finally comes, it will be severe," he said.
Many analysts maintain that the AI earnings cycle and ongoing corporate profit growth have not yet run their course, and that the bull market remains intact. But the record leverage, the surge in inexperienced retail participation — including a near-tenfold jump in accounts opened for minors — and the market's violent reaction to a single social media post all suggest the margin for error is narrowing fast.
