SK Hynix Charts a $20 Billion Factory Blitz Just as a 10% Rout Jolts Its Market

SK Hynix's 213% YTD rally erased in a single session after Broadcom's AI-chip revenue forecast missed estimates, triggering a KOSPI circuit breaker and record retail buying in leveraged ETFs.

The starkest snapshot of today’s AI memory market arrived in two opposing moves within 24 hours. On Thursday, SK Hynix closed at a record 2,298,000 won, capping a 213% year-to-date surge and pushing its market cap past the $1 trillion mark for the first time. By Friday’s close, the stock had plunged 9.92% to 2,070,000 won — shaving roughly $100 billion from its value in a single session.

The trigger came not from Seoul but from California. Broadcom reported its quarterly numbers after the U.S. bell, and the market zeroed in on the AI-chip forecast: $16 billion for the third fiscal quarter of 2026, about 7% below the consensus of $17.2 billion. The full-year projection of $56 billion also missed the $57.6 billion target. Broadcom’s shares cratered more than 15% in after-hours trading, dragging the Philadelphia Semiconductor Index down 5.45%.

That shockwave hit Asian markets at the open, and Seoul took the brunt. The KOSPI fell 5.54% — far deeper than the Nikkei 225’s 1.31% drop or the Shanghai Composite’s 0.74% decline. At one point the index was down more than 6%, triggering a circuit breaker on KOSPI-200 futures that paused algorithmic trading for five minutes. The disproportionate damage in South Korea reflects a risky concentration: Samsung Electronics and SK Hynix together account for 54% of the KOSPI’s market capitalisation, roughly half of daily trading volume this May, and nearly three-quarters of the index’s gains for the year.

Investors in leveraged products got hit hardest. The TIGER SK Hynix Single Stock Leverage ETF dropped 20.11%, and the KODEX version fell 20.29% — both closing at their lowest levels since launch, meaning every buyer so far sits on a loss. Yet retail investors piled into the dip, pouring a net 394.6 billion won into the KODEX SK Hynix Leverage fund.

Against that backdrop of panic, SK Hynix’s management outlined a strikingly ambitious production roadmap. Chairman Chey Tae-won told the Computex conference in Taipei that the company intends to double its wafer output over the next five years, with 2026 capital spending set to “significantly exceed” last year’s roughly $20 billion budget. New facilities include the M15X fab in Cheongju and the planned semiconductor cluster in Yongin. The entire HBM production capacity for 2026 is already fully booked, and the group is preparing mass production of HBM4E, the next-generation high-bandwidth memory that will solidify its role as Nvidia’s lead supplier.

The expansion faces real constraints. Building a new fab now takes three to five years, and bottlenecks in equipment, energy supply and construction capacity are stretching timelines. That tightness, however, also gives SK Hynix sustained pricing power — a fact the company itself underscored by signalling that the price environment for its high-performance AI memory chips should remain favourable well into 2027.

Analysts largely interpreted Friday’s rout as a technical correction after an extraordinary run. Han Ji-young of Kiwoom Securities attributed the selloff to profit-taking, noting that investors had been waiting for a concrete catalyst to reduce positions. Lee Kyung-min of Daishin Securities pointed to another macro pressure: upcoming IPOs from SpaceX, OpenAI and Anthropic may pull global capital out of Korean equities, and the SpaceX listing alone, he argued, could trigger further panic.

Goldman Sachs, however, raised its KOSPI target from 9,000 to 12,000 this week, suggesting the long-term narrative remains intact. Hwang Soo-wook of Meritz Securities expects a lull until the July earnings season, when fresh catalysts — or their absence — will test the market’s resolve. For now, SK Hynix stands at the intersection of a short-term shock and a multi-year capacity push, with its customers already committed and its factories still years from full output.