At a glance: The KOSPI closed at 6,012.44 on October 28, up 6.63%, as SK hynix shares gained 10.89% and Samsung Electronics rose 9.01%. SK hynix reported record quarterly revenue and operating profit, driven by demand for memory used in AI systems. Samsung reported its own results the following day, adding evidence of demand across the sector.
What Happened to the KOSPI?
South Korea’s KOSPI gained 374.10 points on October 28 to close at 6,012.44. It was the index’s first close above 6,000 in ten trading sessions. SK hynix finished at 1.487 million won, up 10.89%, while Samsung Electronics closed at 242,000 won, up 9.01%. Foreign and institutional investors were net buyers on the main market that day.
The timing matters. SK hynix announced its third-quarter results on October 28, the day of the rally. Samsung’s full results came on October 29. The October 28 closing figures therefore show the market’s response to SK hynix’s report and expectations for Samsung—not its response to Samsung’s subsequently published figures.
The move also needs context. A one-day gain of 6.63% is a large change for an equity index, but it does not establish a new, lasting trend. The KOSPI had traded below 6,000 for the preceding nine sessions. The question for investors is whether the earnings that supported the rebound can continue to meet expectations.
What Did SK hynix Report?
SK hynix reported third-quarter 2026 revenue of 104.6155 trillion won and operating profit of 83.3338 trillion won. Its reported operating margin was 80%. Revenue rose 32% from the prior quarter, while operating profit rose 38%. The company said both revenue and operating profit reached quarterly records. These are figures from the company’s October 28 preliminary results, not forecasts.
The product mix explains much of the result. SK hynix said sales of server DDR5 memory increased and shipments of HBM4, a generation of high-bandwidth memory, began to scale. It also reported growth in enterprise solid-state drives used in data centers. Demand and pricing both matter for a memory maker: more shipments can raise revenue, while higher selling prices can have a large effect on profit when factories are operating at scale.
SK hynix also gave investors a view beyond one quarter. It said long-term agreements with 14 customers cover more than 50% of its planned production capacity for 2027 and 2028. The company expects HBM4 to exceed HBM3E in both shipments and revenue in the fourth quarter of 2026. These are company statements about contracts and expectations; they do not guarantee future sales or margins.
Shareholder returns formed another part of the announcement. SK hynix outlined a plan for about 100 trillion won in returns for fiscal 2026 through dividends and share repurchases and cancellations. Earnings, demand visibility and the return plan arrived in the same release, making it difficult to attribute the October 28 share-price gain to one factor alone.
Why Does AI Need So Much Memory?
AI processors need to move data between computing units and memory. High-bandwidth memory, or HBM, is designed to supply data at a high rate for workloads such as training and running AI models. If the processor cannot receive data fast enough, some computing capacity may go unused.
HBM is not the whole market. AI servers also use DRAM for system memory and storage drives to hold datasets and other information. That helps explain why SK hynix discussed server DDR5 and data-center SSDs alongside HBM4. It also helps explain why investors watch both the supply of specialist memory and the prices of other memory products.
Supply cannot always respond at the same speed as demand. SK hynix cited the difficulty of advanced manufacturing processes and the time needed to build facilities when explaining its view that memory demand may exceed supply through 2030. That is the company’s outlook, not an established market forecast. New capacity, changes in customer spending and advances in product design could change the balance.
Samsung’s Results Add a Second Test
On October 29, Samsung Electronics reported third-quarter revenue of 195.3 trillion won and operating profit of 107.4 trillion won. Its Device Solutions division, which includes semiconductors, recorded 147.1 trillion won in revenue and 106.5 trillion won in operating profit. Samsung said its memory business increased HBM4 sales and benefited from demand for server products.
Those results support the view that the latest earnings strength was not confined to SK hynix. They also show why readers should separate a company’s chip business from its consolidated results. Samsung has businesses outside semiconductors, and their performance can differ. Its Device eXperience division reported an operating loss for the quarter even as Device Solutions generated most of the group’s operating profit.
Samsung expects to increase sales of HBM, server DRAM and SSDs. It also reported third-quarter capital expenditure of 29 trillion won and projected about 84.4 trillion won for the full year, with most of that planned for Device Solutions. Capacity spending can help meet orders, but it also raises a question for the next phase of the cycle: how much supply will reach the market, and when?
Is This an Asia-Wide Chip Story?
The October 28 index surge was a South Korean market event. Asian semiconductor production, however, covers more than one country and more than one type of chip. South Korea’s earnings reports centered on memory. Taiwan Semiconductor Manufacturing Company, or TSMC, provides a separate view of demand for chip manufacturing.
TSMC reported third-quarter 2026 revenue of NT$1,494.24 billion, up 50.9% from a year earlier. It said manufacturing processes at 7 nanometers and below accounted for 79% of wafer revenue during the quarter. Its results point to demand for advanced manufacturing, while the Korean reports show demand and pricing in memory. The businesses are linked through computing supply chains, but their sales and margins should not be treated as interchangeable.
That distinction makes the term Asian chip stocks more useful. A memory maker, a foundry and an equipment supplier can all benefit from investment in computing infrastructure, yet each faces different production limits and customer needs. A gain in one company’s shares is not proof that every part of the sector has the same outlook.
Three Risks Behind the Rally
First, earnings expectations can rise faster than earnings. SK hynix delivered record results, but its share price also reflects what investors expect next. If future revenue or margins fall short of those expectations, a strong reported quarter may offer little protection from a decline.
Second, customers and suppliers both make long-term plans. SK hynix’s agreements provide demand visibility, while SK hynix and Samsung plan further capacity investment. Contracts can support production decisions, but new supply and changes in customer budgets can alter market pricing over time. Company guidance should be read as a scenario based on current information, not a guarantee.
Third, index gains can mask differences between stocks. Chipmakers led the October 28 KOSPI advance, and most sectors rose, but not every sector gained. Readers assessing the rally should check individual earnings, valuations and cash needs rather than assuming that a rise in the index applies equally to all listed companies.
What Should Investors Watch Next?
Four measures can test whether the earnings story holds up:
- HBM4 shipments: Does the product gain the share of SK hynix’s shipments and revenue that management expects?
- Server-memory demand: Do DDR5 and data-center SSD sales continue to support revenue beyond HBM?
- Capacity and pricing: Do factory investments meet demand without putting pressure on memory prices?
- Earnings breadth: Do companies across different parts of the chip supply chain report growth, or does performance narrow to a few stocks?
These measures are more informative than a single index close. They also have different reporting schedules. Quarterly results provide confirmed figures for a period that has ended; company outlooks describe what management expects; share prices can react to both before the next results arrive.
FAQ
Why did the KOSPI rise on October 28, 2026?
The KOSPI closed 6.63% higher at 6,012.44 as SK hynix reported record third-quarter results and shares of both SK hynix and Samsung Electronics rose. SK hynix also announced a shareholder-return plan. Samsung published its full third-quarter results the next day, so those figures were not available during the October 28 close.
What is HBM, and why does it matter for AI?
HBM stands for high-bandwidth memory. It supplies data to processors used for computing-intensive tasks. SK hynix reported expanding HBM4 shipments in the third quarter and expects the product to account for more shipments and revenue than HBM3E in the fourth quarter.
Do strong chip earnings mean Asian chip stocks will keep rising?
No. The reported earnings establish what companies earned in the third quarter; they do not determine future share prices. Investors must weigh demand and contracts against production spending, future supply, valuations and the expectations already reflected in stock prices.
Bottom line: SK hynix’s results gave the October 28 KOSPI rally a clear earnings basis, while Samsung’s October 29 report added evidence of demand for AI memory. The next test is whether shipments, pricing and profit can keep pace with the plans companies and investors have made.
