Samsung's HBM4 Yield Surpasses 80% 'Golden Line,' Market Share Set to Overtake SK Hynix Next Year

The battle for leadership in global high-bandwidth memory (HBM) is intensifying. SK Hynix (000660KS) is陷入 a labor-management standoff over bonus and compensation plans, casting uncertainty over its HBM4 expansion. In contrast, Samsung Electronics (005930KS) is accelerating its efforts, with HBM4 yields now exceeding 80%—the so-called 'golden yield.' UBS forecasts that Samsung’s HBM bit shipment market share could rise to 41% by 2027, narrowly overtaking SK Hynix’s projected 39%, potentially shifting the global HBM leadership.

SK Hynix concluded its fifth round of negotiations with the union on August 9, but both sides failed to reach an agreement on the bonus scheme. The core dispute centers on the distribution method of the 'profit-sharing bonus.'

Under SK Hynix’s original profit-sharing mechanism, 10% of the semiconductor division’s annual operating profit was allocated to an employee bonus pool. Of this, 80% was paid out in cash the same year, while the remaining 20% was disbursed over two years. The system was initially set to last ten years.

Last year, labor and management agreed to pay all bonuses in cash. However, this year, management proposed a new plan to pay more than half of the profit-sharing bonuses in company stock, with a lock-up period, causing negotiations to stall. The union is particularly frustrated that management seeks to revise, after just one year, a bonus agreement reached only after 11 rounds of talks.

Management argues the stock-based payment aims to reduce large cash outflows from rapidly rising bonuses, balancing employee compensation, capital expenditure, and shareholder returns. It also believes stock incentives better align employee interests with long-term company value.

The union opposes the arrangement, viewing it as transferring the risks of stock price declines and capital gains tax burdens onto employees. Additionally, management’s proposal for flexible salary adjustments during loss periods has made no progress, with the union seeing it as essentially a tool for wage cuts.

Labor Disputes May Impact HBM4 Expansion

Worker dissatisfaction has spread from negotiation tables into the company. A preparatory committee for an SK Hynix union, covering production and technical office roles, formed on August 5 and within three days attracted over 3,500 participants—about 10% of the workforce—and formally applied for union registration on August 8.

Analysts warn that if the labor dispute remains unresolved, it could become a variable affecting SK Hynix’s mass production ramp-up of its sixth-generation HBM product, HBM4.

SK Hynix originally planned to begin mass shipments of HBM4 in Q2 and launch large-scale expansion in the second half. If collective actions spread further into production lines, supply timelines may face pressure.

As SK Hynix grapples with labor issues, Samsung Electronics is accelerating HBM4 mass production, extending competition between the two South Korean memory giants beyond technology development into capacity and market share.

Samsung Achieves 80% 'Golden Yield' in HBM4

South Korean media report that Samsung Electronics’ HBM4 yield has recently reached 80%. In the semiconductor industry, an 80% yield is known as the 'golden yield,' indicating defect rates are under control, output is stabilizing, and profitability is achievable.

Notably, when Samsung began mass-producing HBM4 in February this year, yields were below 60%, but it took only about six months to reach 80%.

Industry insiders note that Samsung’s original target for year-end yield was 80%, but with expanded production scale in the second half, process improvements have exceeded expectations, shifting HBM market competition from R&D toward capacity battles.

Samsung Memory Business Senior Vice President Kim Jae-joon stated in the Q2 earnings call that HBM4 revenue in Q3 will more than double from the previous quarter, and HBM4 will account for over 60% of total HBM revenue in the second half.

Samsung has set a goal to increase its HBM market share to around 38% by year-end—matching its current share in the traditional DRAM market—indicating its ambition to align HBM business performance with its DRAM market position.

Samsung Poised to Overtake by 2027

Nonetheless, SK Hynix retains strong defensive capabilities in the HBM4 race. Kim Ki-tae, VP of Sales and Marketing for HBM at SK Hynix, emphasized that true HBM4 competitiveness requires stable yield, quality, and large-scale supply capability. Currently, SK Hynix’s HBM4 mass production yield and quality levels are approaching those of the matured previous-generation HBM3E.

Industry analysis suggests SK Hynix’s HBM4 yield has also entered the 80% range. While Samsung is catching up rapidly, the ultimate deciding factor will be subsequent mass production and supply capacity.

A recent UBS report estimates that based on HBM bit shipments, SK Hynix will maintain first place in 2026 with a 48% market share. However, by 2027, Samsung’s share is expected to rise to 41%, slightly surpassing SK Hynix’s 39%.

HBM bit shipments measure the total memory bit capacity of HBM chips, reflecting actual supply scale. The market widely believes the rivalry between Samsung and SK Hynix may ultimately be decided in the upcoming HBM4E market, scheduled for mass production next year.

Samsung holds an advantage in expansion potential, while SK Hynix excels in volume production quality. The speed at which both companies expand supply in Q4 may become a critical factor shaping the future HBM market landscape.