How Samsung and SK hynix Compare in HBM

On the latest public estimate, SK hynix still has the larger share of the market for HBM, the memory that sits beside AI chips, but Samsung Electronics has closed much of the gap. Counterpoint Research put SK hynix at 50% of HBM revenue in the second quarter of 2026 and Samsung at 33%, up from 21% a quarter earlier. The companies’ own releases and the research firms do not always tell the same story. This guide sets the public figures side by side. It does not pick a winner.

Second-quarter results are converted at 1,549.4 won per dollar, the 15:30 Korea time close on June 30, 2026, the last day of the quarter (Bank of Korea, ECOS). Other dates use that day’s 15:30 close, stated where they appear.

What is HBM, in plain words?

HBM stands for high bandwidth memory. It is DRAM, the working memory found in phones and PCs, built in a different shape.

Ordinary DRAM chips sit on memory modules some distance from the processor. HBM stacks thin DRAM chips on top of each other, links them with tiny vertical connections through the silicon, and places the stack right next to the processor inside the same package. Being so close, it can use a very wide connection: Samsung says HBM4 doubles the data lines per stack from 1,024 to 2,048 compared with HBM3E.

The generations so far, as SK hynix lists them, are HBM, HBM2, HBM2E, HBM3, HBM3E and HBM4. Both companies have also sent customers samples of the next step, HBM4E.

Why do AI accelerators use HBM?

AI accelerators, such as the graphics processors that train and run large language models, spend much of their time moving data in and out of memory. If memory cannot keep up, the processor waits. HBM’s wide, short connection moves far more data per second than ordinary DRAM: Samsung says its HBM4 reaches up to 3.3 terabytes per second per stack, 2.7 times its HBM3E.

Power matters too, because data centers pay for every watt. SK hynix says its HBM4 is more than 40% more power-efficient than the generation before; Samsung gives 40% over its HBM3E. These are company claims, not independent tests.

What share of the HBM market does each company have?

Neither company reports its HBM revenue separately, so market shares are research firms’ estimates. Counterpoint Research’s quarterly table, published on September 2, 2026, measures share by revenue and lists three suppliers:

• Q2 2025: SK hynix 64%, Micron 21%, Samsung 15%
• Q1 2026: SK hynix 58%, Samsung 21%, Micron 21%
• Q2 2026: SK hynix 50%, Samsung 33%, Micron 18%

The Korean outlet Edaily reported the same Q2 figures on September 3. The Q2 shares add up to 101% because of rounding.

TrendForce, another research firm, tracks HBM by bit output, meaning volume rather than revenue, mostly in paid reports. The public summary of its June 23 2026 bulletin says “diverging HBM4 certification timelines are reshaping 2026 market share”, but gives no percentages. We could not find a public TrendForce figure for 2026 to set beside Counterpoint’s. Revenue and volume shares can differ, because prices vary by generation and customer.

How do their latest quarterly results compare?

The two companies are built differently. SK hynix reports a single semiconductor segment, almost all DRAM and NAND flash memory. Samsung’s chip division, Device Solutions (DS), also includes its foundry and System LSI businesses, and the rest of Samsung makes phones, TVs, appliances and displays. Samsung’s press release gives no separate figure for its memory business.

Second quarter of 2026 (April to June), both record quarters:

• SK hynix: revenue 79.32 trillion won (about US$51.2 billion), operating profit 60.54 trillion won (about US$39.1 billion), a 76% operating margin.
• Samsung, DS division: revenue 127.5 trillion won (about US$82.3 billion), operating profit 89.2 trillion won (about US$57.6 billion), a margin of about 70%.
• Samsung, whole company: revenue 171.5 trillion won (about US$110.7 billion), operating profit 89.5 trillion won (about US$57.8 billion). The chip division made almost all of it; phones and networks lost 0.7 trillion won.

SK hynix’s release said its figures could still change during the audit.

On October 8 Samsung guided to third-quarter sales of about 195 trillion won (about US$145.7 billion) and operating profit of about 107.4 trillion won (about US$80.2 billion), at 1,338.5 won per dollar that day. The guidance has no division breakdown and comes before the audit. Samsung has scheduled its full third-quarter results and earnings call for October 29, according to a company notice dated October 8. SK hynix has scheduled its third-quarter earnings call for October 28, according to a US Securities and Exchange Commission filing dated October 14.

Currency matters here: the won strengthened from 1,549.4 per dollar on June 30 to 1,338.3 on October 14, so the same won profit is worth about 16% more dollars at the October rate.

Where do they stand on HBM3E and HBM4?

Both companies claim to have been first with HBM4, at different steps:

• SK hynix, on September 12, 2025, said it had completed HBM4 development and prepared mass production “for the world’s first time”. On July 29, 2026 it said it “began mass shipments of HBM4 in the second quarter”, and that it had completed HBM4E sample shipments in the first half.
• Samsung, on February 12, 2026, said it had begun HBM4 mass production and shipped commercial products to customers, “a first in the industry”. On July 30 it said it had “scaled up HBM4 sales” and shipped “the industry’s first HBM4E samples to major customers”.

TrendForce’s June 23 bulletin gave a different picture of SK hynix’s timing. It said Samsung was first to complete HBM4 validation and begin shipments in the second quarter, while “interface sync issues” pushed SK hynix’s mass production to the third quarter. SK hynix’s own release, five weeks later, said mass shipments began in the second quarter. Neither source explains the gap, and “mass production” may not mean the same thing to each.

Which customers have they disclosed?

Neither company names its HBM customers in these releases. SK hynix said it has long-term agreements with “around 10 customers, including key strategic partners”. Samsung refers to “major customers”.

Press reports name Nvidia. Yonhap News reported on January 28, 2026, citing industry sources, that Nvidia had allocated about two-thirds of the HBM4 for its Vera Rubin platform and other products to SK hynix. Neither company nor Nvidia confirmed this report in the material cited here.

How have the two share prices moved?

Moves to the KRX close on October 14, 2026, from the close on each start date:

• Since October 6 (5 sessions): Samsung Electronics −14.71%, SK hynix −19.97%
• Since September 10 (20 sessions): Samsung −13.75%, SK hynix −23.42%
• Since July 14 (60 sessions): Samsung −11.79%, SK hynix −25.82%
• Since April 15 (120 sessions): Samsung +9.95%, SK hynix +24.91%

Over the same periods the KOSPI 200 map, weighted by market value, moved −13.81%, −15.12%, −13.12% and −0.45%. SK hynix moved more than Samsung in both directions. Our guide to why the KOSPI is so volatile looks at swings like these.

On October 14 Samsung’s common shares were worth about 1,356 trillion won (about US$1.01 trillion) and SK hynix’s about 1,037 trillion won (about US$775 billion), at 1,338.3 won per dollar. On October 13 the two made up 52.4% of the our KOSPI 200 map by market value, which is why they fill so much of the KOSPI heatmap. Our interactive market map shows their moves over each period.

A share price reflects the whole company. Samsung’s includes phones, TVs, foundry and displays, so it is not a measure of its HBM business alone. And every figure here describes the past; none of it shows how the next quarter will turn out.

For access from abroad, see our guides to the SK hynix ADR and the Korean shares and to holding Samsung shares from outside Korea.