SK Hynix's 54 Trillion Won Wager: The Earnings Power Behind the Building Spree

SK Hynix posts record 76% operating margin on AI memory demand, signs five-year HBM4 supply deals, and boosts shareholder returns amid massive capex.

The market has already voted on SK Hynix's capital return promises — the stock has climbed roughly 12 percent since the company dangled additional buybacks and a 375 won dividend just over a week ago. But the more consequential story is unfolding beneath the share price: a record-breaking earnings report that gives the company the financial firepower to fund a 54.3 trillion won expansion program while still paying shareholders handsomely.

The Numbers Behind the Narrative

SK Hynix's second-quarter results for fiscal 2026, released on Tuesday, were striking even by the standards of an AI-crazed semiconductor sector. Revenue hit 79.3 trillion won, up 257 percent year over year, while operating profit surged 557 percent to 60.5 trillion won. The operating margin reached a company-record 76 percent.

What separates this quarter from a simple cyclical spike is the contractual visibility now baked into the business. SK Hynix has commenced mass production of HBM4 memory chips for major customers and locked in five-year supply agreements with roughly ten key clients. That structural demand — not just hope — is what underpins the board's decision to commit 54.3 trillion won to new fabrication facilities in Yongin and Cheongju, with cleanrooms not expected to come online until late 2028 at the earliest.

Morgan Stanley flagged the same logic on Wednesday, pointing to management's pledge to return more than 50 percent of cumulative free cash flow between 2025 and 2027 to investors. The message: buybacks and record capital expenditure are not competing priorities — they are both funded from the same expanding cash flow stream.

Labor Signs Off, Ratings Follow

A quieter but telling development came on Wednesday, when SK Hynix and its union reached a tentative agreement on a 6.3 percent base salary increase. The deal also calls for 60 percent of performance-based annual bonuses to be paid in shares rather than cash, a concession designed to preserve cash for AI investments. The workforce is effectively co-signing the company's investment strategy rather than resisting it.

That signal did not go unnoticed by S&P Global, which on Thursday upgraded SK Hynix's long-term issuer rating from "BBB+" to "A-" with a stable outlook. The agency cited robust profitability from AI-driven memory demand and improved cash flow visibility thanks to the long-term customer contracts — external validation of the same thesis the HBM4 supply agreements suggest.

The Valuation Debate

The stock's trajectory invites scrutiny. Shares have gained 160 percent since the start of the year and, despite sitting roughly 16 percent below their 50-day moving average, remain about 35 percent above the 200-day average. That looks overheated on the surface.

Nomura disagrees. The brokerage concluded on Thursday that the stock is "gravely undervalued" at an estimated price-to-earnings ratio of 3.8 for 2026, reaffirming a buy rating with a target of 4.7 million won. KB Securities went further last week, calling the shares "extremely undervalued" and pointing to a projected combined operating profit of 641 trillion won for Samsung and SK Hynix in 2026.

The China Wildcard

Meanwhile, SK Hynix is exploring options for its plant in Chongqing, China, according to Bloomberg. The company is reportedly considering bringing in an investor to accelerate growth there, with advisers already engaged and a potential valuation of around $3 billion under discussion. No decision has been made, but a partial sale or equity injection would free up capital without surrendering operational control of the core business in South Korea.

The Risks That Loom

The bear case centers on timing. The 54.3 trillion won commitment stretches across years, with construction on both Yongin's "Y2" facility — priced at 35.2 trillion won — and Cheongju's "M17" plant — at 19.1 trillion won — not slated to begin until 2027. The Wall Street Journal pegs the total capacity expansion in South Korea at roughly $38 billion.

That means costs will pile up well before the market knows whether AI memory demand will still justify the added capacity. A slowdown in customer orders or delays in the production ramp would leave SK Hynix exposed to high fixed costs alongside elevated shareholder payout expectations. The stock's 43 percent gap from its 52-week high serves as a reminder that this story has been over-celebrated before, with painful consequences.

The first concrete test comes with the third-quarter announcement detailing the additional capital returns. The real reality check follows in February, when the Yongin cluster is slated to begin production. Between now and then, the market will be weighing whether SK Hynix's record earnings power can carry the weight of its own ambition.