The world's leading supplier of AI memory chips shed 15% in Seoul on Monday, freezing the Korean market and laying bare how stretched the AI hardware trade has become.
SK Hynix built its record-breaking year on artificial intelligence. On Monday, the same AI trade turned against it.
Shares of the South Korean chipmaker, whose high-bandwidth memory sits inside the Nvidia accelerators that run the world's largest AI models, collapsed 15.4% in a single Seoul session. That was the steepest one-day drop in the company's history, and it landed just one trading day after a record-breaking Nasdaq debut.
The fall was violent enough to drag down an entire national stock market.
A Record Debut Gives Way to a Record Rout
SK Hynix's American depositary receipts began trading in New York on Friday, July 10. They opened at $170, roughly 14% above the $149 reference price, and closed their first day up 12.8%. The offering raised $26.5 billion, the largest share sale ever completed by a non-U.S. company, surpassing the roughly $25 billion Alibaba pulled in during its 2014 New York flotation. Investor appetite was ferocious, with the deal oversubscribed more than sevenfold. Each ADR represents a tenth of a Seoul-listed share.
Then the weekend ended.
When Seoul reopened on Monday, foreign and institutional investors bolted. Retail traders, who had powered much of the year's rally, began redirecting their attention toward the newly available U.S. line. By the close, the record was set, according to LSEG data: the sharpest single-session loss the stock had ever booked.
The damage spread quickly. Samsung Electronics, the other giant anchoring Korea's index, dropped close to 11%. Together the two names pulled the benchmark Kospi down almost 9%, tripping a circuit breaker and forcing a 20-minute halt in trading. It was the seventh time this year that Korean markets hit that kind of emergency brake. Exchange data showed overseas investors pulling about 1.7 trillion won, near $1.1 billion, out of Korean equities, with the bulk of that selling landing on SK Hynix.
By Monday's close the company's market value had slipped to around $875 billion, down from the $1 trillion threshold it had crossed earlier in the year. Even after the plunge, the stock remained far above its starting point, worth roughly six times what it was twelve months ago.
The unease reached beyond Korea. Japan's Nikkei 225 fell about 2%, and memory rival Kioxia tumbled close to 13%. Renewed tensions in the Middle East and fresh doubts about whether the AI rally had raced ahead of actual earnings weighed on markets across the region. U.S. memory peers slid in premarket trading, with Micron down 4.5% and Western Digital off 5.2%.
One Company, Two Prices, a 37% Gap
The sell-off left an unusual distortion in its wake.
SK Hynix's U.S. ADRs, which had closed Friday at $168, were changing hands near $152.50 before Monday's New York open, a decline of about 9%. Even after that slide, the American receipts carried a premium of roughly 37% over the price of the identical shares in Seoul.
Cross-listed stocks often trade richer in the United States, where deeper liquidity and broader investor access tend to support higher valuations. James Ooi, a market strategist at Tiger Brokers in Singapore, pointed to those structural advantages, but noted the gap is hard to close because converting Korean shares into ADRs involves real friction. For comparison, Taiwan Semiconductor Manufacturing's U.S. receipts trade at a premium closer to 13% to 14% over its Taipei shares. SK Hynix's gap, at nearly triple that, looks less like a durable feature of the stock and more like a dislocation waiting to be resolved.
Geared Bets Cut Both Ways
Much of the year's wild price action has been amplified by a boom in single-stock funds that use borrowed money to magnify daily moves.
In Hong Kong, a 2x product from fund manager CSOP that aims to deliver twice SK Hynix's daily return lost more than a third of its value on Monday, its worst session since it began trading in October. The same mechanics that supercharged gains on the way up turned brutal on the way down. Adding to the pile, a pair of new geared SK Hynix funds, one built to double the daily upside and one designed to profit when the stock falls, were set to begin trading on the Cboe exchange that same Monday.
These products have turned SK Hynix into a favored vehicle for traders chasing the AI memory shortage. They have also made the stock a faster, sharper ride in both directions.
Nerves Before the Numbers
Timing sharpened the anxiety.
SK Hynix is scheduled to report second-quarter results on July 22, and sentiment soured as that date approached. Ryu Young-ho, a senior analyst at NH Investment & Securities, tied Monday's drop partly to profit-taking now that the U.S. listing was complete, and partly to caution about the coming earnings. He flagged a specific worry: investors had expected shipments of the company's next-generation HBM4 chips to ramp up from the second quarter, and that increase does not appear to have arrived at scale.
Ryu pointed to a subtler issue as well. Because SK Hynix leans more heavily on HBM than Samsung does, it stands to gain less from the recent surge in prices for conventional DRAM, where its crosstown rival has broader exposure.
None of this implies a weak quarter in absolute terms. Analysts still expect the April-to-June period to break records, with an LSEG SmartEstimate putting operating profit near 65.5 trillion won and some brokerage forecasts reaching into the 60 to 70 trillion won range. A result at that level would roughly double the company's already record first-quarter profit and imply an operating margin approaching 77%, which would rank among the fattest of any major technology company on the planet. The worry on Monday was narrower: whether reality can keep clearing a bar that investor expectations have raised so far, so fast.
The 2027 Question That Splits the Market
Underneath the day's mechanics sits the argument that will decide where SK Hynix goes next, and it comes down to a single year.
Chief Executive Kwak Noh-jung has staked out an aggressively bullish position. In a Reuters interview timed to the Nasdaq debut, he said 2027 would be the worst year the industry has ever seen from a supply standpoint, arguing that customer demand will keep outrunning the company's ability to produce chips well beyond 2030. His view is echoed at the top of SK Group, whose chairman warned earlier this year of a structural wafer shortage exceeding 20% that would not close until after the decade turns.
The bull case rests on the company's grip on the most valuable corner of the memory market. SK Hynix led the high-bandwidth memory segment with a 58% revenue share in the first quarter, according to Counterpoint Research, while Samsung and Micron each held 21%. Its edge in the next generation looks firmer still. The company has reportedly locked up close to 70% of Nvidia's HBM4 orders for the upcoming Vera Rubin AI platform, well ahead of earlier market estimates, and its chips feed the AI systems of customers led by Nvidia and Alphabet's Google.
The bears are looking at the same numbers and drawing the opposite conclusion.
Analysts at Morningstar expect the wave of fresh capacity coming online across 2027 and 2028 to loosen today's tight supply and eventually push prices lower. Lorraine Tan, a director at the firm, values the stock at $160 per ADR and cautions that the current upcycle, strong as it is, still bakes in an eventual return to normal. She raised a pointed concern about the demand side of the AI story: monetization remains unproven, and the profitability of marquee buyers such as OpenAI looks strained as their funding tilts increasingly toward debt. If that spending wobbles, the shortage thesis holding up SK Hynix's valuation wobbles with it.
That tension, between a company convinced the shortage is only beginning and a market unsure the AI boom can keep paying for it, is what Monday's crash exposed. The July 22 earnings report will be the next place it gets tested.
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