SK hynix fell 14.7% on July 28 and another 9.6% on July 29. At the same time, it reported record second-quarter revenue of 79.3187 trillion won, operating profit of 60.5426 trillion won, and an operating margin of 76%. Record earnings and a record-scale stock decline occurred together.
The contradiction shows that stocks react to changes in expectations, not just absolute earnings. The share price and investor positioning had already reflected HBM leadership and scarce AI memory. When results fell short of some high forecasts and concerns about AI spending and Chinese competition grew, the premium and leverage contracted at the same time.
Key Takeaways
Record earnings were below even higher expectations, and a shrinking HBM premium was amplified by forced deleveraging.
| Item | Figure | Meaning |
|---|---|---|
| July 28 | -14.7% | Heavy selling on AI-investment and China-competition concerns |
| July 29 | -9.6% | Expectation reset and liquidation continued after earnings |
| Q2 revenue | KRW 79.3187T | Up 257% from a year earlier |
| Q2 operating profit | KRW 60.5426T | Up 557%, with a 76% operating margin |
How Strong Were the Results?
SK hynix reported second-quarter revenue of 79.3187 trillion won and operating profit of 60.5426 trillion won. Revenue rose 257% from a year earlier and operating profit increased 557%. A 76% operating margin showed how HBM and high-value DRAM pricing and mix drove profit.
The company said HBM4 met customer specifications and that it planned a full production ramp in the second half. Current AI-memory demand and technology leadership remain strong, so the selloff is not evidence that the HBM business suddenly collapsed.
Source: SK hynix – Q2 2026 business results
Why Did the Stock Fall After Record Earnings?
First, the consensus bar was extremely high. Some market estimates pointed to operating profit near 64.1 trillion won. The actual 60.5426 trillion won was a record but below that level. Stocks react to whether results improved relative to expectations, not whether they were simply good or bad.
Second, SK hynix carried an HBM-leadership premium. The valuation assumed faster qualification and stronger supply execution than competitors. Reports of Chinese memory expansion or more efficient AI models can reduce long-run pricing and volume assumptions even before commercial scale is proven.
Third, investors questioned the durability of financing across the AI ecosystem. Concern that GPU and server investment relied partly on supplier funding and large commitments rather than end-customer returns could reduce expected HBM-demand growth.
Fourth, the KOSPI plunge triggered forced deleveraging. The July 28 decline breached collateral and risk limits, creating selling the next day that was not directly related to the earnings release. When bids are thin, even record profit may not provide immediate price support.
Source: Reuters – Korean chip selloff and competition concerns
Why the U.S. ADR Matters Alongside the Korean Shares
SK hynix’s U.S. ADR represents 0.1 common share per ADS and was offered at $149. Korean common shares, the ADR, exchange rates, and arbitrage are linked, allowing risk reduction in one time zone to affect the next market session.
An ADR trading below its offer price can weigh on sentiment before Korea opens, while a Korean selloff can feed back into U.S. trading. Exchange rates, costs, and liquidity complicate a direct price comparison, so direction and volume are more useful than matching raw prices.
- Whether the Korean shares and U.S. ADR form lows together
- The production speed and yield after HBM4 customer qualification
- HBM and DRAM contract prices and customer inventories
- When capacity expansion could turn scarcity into oversupply
Source: SEC – SK hynix ADR final prospectus
Outlook: Balancing HBM Leadership and Expectations
The bullish path requires HBM4 production to proceed on schedule, customer orders and pricing to hold, and forced selling in Korea and the United States to subside. Record profit converting into cash flow and shareholder returns could help establish a valuation floor.
The base case keeps the business strong while the premium gradually contracts. The bearish case combines slower AI investment, competitor supply, lower memory prices, and continued deleveraging. A durable recovery requires earnings-estimate cuts to stop, not just one rebound session.
Source: AP – SK hynix earnings and July 29 stock reaction
Three Paths From Here
| Path | Confirmation |
|---|---|
| Bull | HBM4 production, pricing, and orders hold as forced selling eases |
| Base | Operations stay strong while the HBM premium contracts gradually |
| Bear | Slower AI spending and more supply weaken memory pricing |
What to Monitor
| Indicator | What it shows |
|---|---|
| HBM4 production and yield | Whether qualification converts into volume |
| HBM and DRAM contracts | Whether pricing and product mix hold |
| Earnings estimates | Whether the downward revision cycle stops |
| Korean shares and U.S. ADR | Whether selling pressure eases in both markets |
| Capacity and supply | When today’s scarcity could become future excess |
FAQ
Should record earnings automatically lift the stock?
No. The stock responds to results relative to expectations. A high HBM premium and crowded positioning can contract even when absolute earnings are excellent.
Is a 76% operating margin sustainable?
It reflects a favorable HBM and memory-pricing mix. Competition, contract pricing, product mix, and capacity investment can change it, so it should not be treated as permanent.
Does the plunge mean HBM demand is over?
No. The company said HBM4 met customer specifications and is scheduled for a second-half ramp. The market is adjusting the expected rate and profitability of future growth.
What would best confirm a rebound?
Actual HBM4 production, stable contract pricing, an end to earnings-estimate cuts, and synchronized stabilization in the Korean shares and U.S. ADR.
Public Sources
- SK hynix – Q2 2026 business results
- SEC – SK hynix ADR final prospectus
- Reuters – Korean chip selloff and competition concerns
- AP – SK hynix earnings and July 29 stock reaction
This analysis summarizes market structure and confirmation signals from public information. It is not a recommendation to buy or sell any security.
