What Are Memory Stocks? Micron, Samsung and Sk Hynix: Who Is the Best HBM Pick? Where Are the Opportunities in Taiwan Stocks?

Memory acts as an intermediate storage for data, broadly categorized into DRAM and HBM, where data is lost after power is cut, and Flash, which retains data after power-off. In the current AI infrastructure boom, HBM is in the shortest supply. HBM is a core component of AI servers; due to complex manufacturing processes and low yields, its production capacity is smaller and its prices are higher.

HBM

Micron, SK hynix, and Samsung are currently the world's leading mass-production suppliers of HBM, which Nvidia's H100 and B200 chips rely heavily upon. To date, the latest technical standard in mass production is HBM4, the sixth generation of high-bandwidth memory, which has become a standard feature for Nvidia's Vera Rubin platform and AMD's MI450. The more advanced and efficient HBM4E has not yet entered mass production but is already included in the roadmaps of major manufacturers.

Currently, the HBM market suffers from a severe supply-demand imbalance, with the three major leaders' 2026 HBM production capacity fully sold out and orders booked through 2027 or even 2028. The industry generally expects this extreme shortage to ease only in 2028.

DRAM

DRAM is currently the most critical memory component for personal computers, servers, and data centers. The primary suppliers remain Samsung, SK hynix, and Micron, which collectively hold approximately 95% of the global market share. As these companies shift their primary production capacity to HBM, the supply shortage of DDR5 and DDR4 has led to price increases that actually exceed those of HBM.

Currently, the supply of DDR4 primarily comes from Taiwanese manufacturers, with Nanya Technology now one of the few global vendors capable of providing a stable supply of 16nm process DDR4.

Flash

Flash refers to flash memory; its distinction from DRAM is that data is not lost after power is disconnected. NAND Flash is the most mainstream type of Flash, while NOR Flash is another, less common variety.

NAND is the core of solid-state drives (SSDs) and is also widely used in USB drives and mobile phone storage. In the NAND market, Samsung and SK hynix remain the market share leaders, while Kioxia and SanDisk (SNDK) are also key players. SanDisk completed its spinoff from Western Digital (WDC) in 2025, returning to its status as an independent listed company focusing on products such as SSDs.

Currently, all these types of memory are in severe shortage, though for different reasons. HBM demand is directly driven by AI computing requirements; the DRAM shortage is caused by the three major manufacturers repurposing DRAM lines for HBM; the NAND shortage results from forced production cuts by Samsung and SanDisk to offset heavy losses from previous oversupply; and the NOR shortage stems from Taiwanese manufacturers strategically cutting NOR production to increase NAND output.

Currently, in the memory industry's hottest HBM market, the three giants are Micron, SK Hynix, and Samsung; only these three companies can produce HBM4 chips. SK Hynix and Samsung are South Korean enterprises listed in South Korea.

In addition, memory investment targets in the U.S. stock market include Western Digital, which focuses on NAND Flash and HDD storage; SanDisk, which focuses on SSDs; and the HDD manufacturer Seagate (STX) among others.

The Taiwan stock market primarily consists of niche DRAM, NAND controllers, and memory modules.

Chip design and manufacturing plants

Memory module manufacturers: ADATA (3260), TeamGroup (4967), Transcend (2451), Innodisk (5289)

Testing and packaging: Powertech Technology (6239), AP Memory (6531)

Currently, the HBM market is a three-way race where SK Hynix holds a 50% market share, leading the other two companies significantly and maintaining this advantage over the long term. Samsung follows with a current market share of around 30%, while Micron trails with only 20-25%. As Micron was excluded from NVIDIA's Rubin supplier list this year, the market share gap may widen further.

SK Hynix has long maintained its lead thanks to its first-mover advantage. The company began HBM R&D in 2009 and collaborated with AMD to develop the world's first HBM chip in 2013. In contrast, Samsung only began mass-producing first-generation HBM2 in 2016 and did not treat HBM as a core business until the AI boom. Micron similarly "bet on the wrong horse" by wagering on its proprietary HMC (Hybrid Memory Cube) technology during the early stages of HBM development.

SK Hynix has the longest-standing partnership with NVIDIA, with the two being deeply intertwined. SK Hynix participated in the architectural design of NVIDIA GPUs during the R&D phase and was quicker to obtain specifications for the next-generation HBM4, allowing it to prepare in advance and lead the way in the verification process.

Leveraging years of collaborative experience, SK Hynix developed its proprietary MR-MUF packaging technology. This technology offers superior thermal performance compared to Samsung's TC-NCF process, along with higher stability and yields, allowing SK Hynix to establish a technological edge.

Beyond its closer relationship with NVIDIA, SK Hynix's depth of cooperation with TSMC (TSM) is also the highest among the big three: it is more than a simple upstream-downstream supply chain relationship, as the two have engaged in joint R&D. The structure of bufferless HBM4 is a product of this collaboration.

Samsung and Micron have also established partnerships with TSMC, but for Samsung, TSMC is a formidable competitor to its own foundry business. Samsung’s decision to outsource packaging integration to TSMC while continuing to produce its own memory and logic layers was a reluctant move necessitated by its failure to pass NVIDIA's qualification.

Given its first-mover advantage and closer collaboration with NVIDIA and TSMC, SK Hynix has secured the highest market share in the HBM market.

Samsung had fallen significantly behind its competitors in recent years because it initially insisted on TC-NCF technology. Poor thermal efficiency led to heat accumulation and signal jitter, preventing it from passing NVIDIA's 12-layer HBM3E qualification. However, in the second half of 2025, Samsung overcame these issues and successfully passed NVIDIA's verification. Its HBM product roadmap is not only back on track, but it even demonstrated transmission speeds slightly higher than SK Hynix in HBM4 specification tests.

Micron's market share ranks last among the big three. Besides its early strategic misstep, the primary reason is insufficient capacity. While Samsung and SK Hynix operate massive memory production bases in South Korea, Micron's facilities are geographically dispersed, making it difficult to compete with the economies of scale achieved by the Korean firms. However, this may also relate to Micron's business strategy; although it can produce the lowest-power HBM3E chips among the trio, it avoids price wars for the mass market and instead sells its limited supply only to top-tier customers.

Although SK Hynix currently holds the largest market share, HBM technology is still undergoing iterative updates and the market continues to grow. Its prospects must be examined from perspectives such as technology, order volume, production capacity, and capital efficiency.

Technological Advantages: No Absolute Leader

Currently, SK Hynix's MR-MUF packaging technology offers the best heat dissipation, while Samsung utilizes TC-NCF technology and Micron uses an optimized version of TC-NCF. These two technological paths each have advantages in different application scenarios: although SK Hynix's MR-MUF has excellent heat dissipation, it suffers from warping when stacking more than 16 layers; the TC-NCF technology used by Samsung provides better structural stability, ensuring chips do not deform during ultra-high-layer stacking.

However, to completely resolve heat dissipation issues in ultra-high-layer stacking for the launch of HBM4 products, all three companies are currently secretly developing hybrid bonding technology. This involves completely eliminating solder balls in favor of direct copper-to-copper connections, fundamentally disrupting the MR-MUF and TC-NCF technologies that both require solder balls for chip bonding. Investors should closely monitor the progress of these three companies in this technology; a breakthrough by Samsung could allow it to overtake SK Hynix, while success for SK Hynix would further widen its lead.

Micron's technological advantage lies not in heat dissipation but in power consumption control. The fundamental reason is that Micron was the first to achieve mass production using the 1̢ process, which allows for smaller die sizes and finer circuits. Consequently, at the same storage capacity, Micron's chips require lower driving voltage and are more energy-efficient. Although Samsung and SK Hynix have caught up with the 1̢ process and are moving toward 1̳, Micron has leveraged its early start to secure a significant portion of NVIDIA's 2026 pre-orders for energy-efficient HBM3E and maintains its lead in power-saving optimization technology.

While there are stark differences in market share among these three companies, looking ahead to the long term, the differences between the three giants in heat dissipation, stacking, and power consumption control technologies will narrow. Therefore, in the short term, whichever company achieves a technological breakthrough first will see higher stock price returns; however, in the long run, technology may not be the deciding factor, as production capacity, capital efficiency, and ecosystem building become more critical.

Order Scale: Customized HBM to Redraw Market Landscape

SK Hynix holds the highest market share. Benefiting from the "Iron Triangle" relationship between NVIDIA, TSMC, and SK Hynix, SK Hynix's orders have the highest priority in the HBM market (since NVIDIA is the market's largest customer), constituting its greatest current advantage. Even if HBM supply falls short of demand in 2026 and it becomes a complete sellers' market where NVIDIA "buys whatever is available," SK Hynix's advantage persists as it remains NVIDIA's preferred supplier with the highest supply ratio.

However, the dynamics of the HBM market are quietly changing. Besides NVIDIA, Google (GOOG) (GOOGL) , AWS, Meta (META) and other cloud service providers have joined the ranks of those pre-ordering customized HBM, which will rewrite the current market landscape. There were previous rumors that Google might expand its cooperation with Samsung, potentially awarding TPU foundry orders to Samsung or purchasing HBM from them. Additionally, other tech giants developing their own chips, such as AWS and Meta, also have demand for HBM.

This change is undoubtedly a turning point for Samsung, which possesses foundry capabilities, and is also favorable for the SK Hynix-TSMC alliance. However, Micron will need to prove its flexibility in the customized market.

Micron is a pure-play memory company and lacks vertical integration capabilities; it must outsource its logic base dies and packaging to TSMC, leading to higher coordination costs compared to its competitors. Furthermore, Micron's production capacity is smaller, and although it is expanding in regions like Taiwan and Japan, it remains difficult to catch up with rivals in the current production cycle. Smaller capacity means Micron cannot take on very large orders and has a lower margin for error.

Therefore, when considering future order visibility, beyond focusing on current market share, it is more important to monitor the dynamic status of NVIDIA's HBM suppliers and the partners chosen by other cloud service providers for HBM. Based on the current situation, SK Hynix possesses the most obvious order advantage.

Production Capacity: The Variable Lies in Samsung's DRAM Lines

Samsung possesses the world's largest wafer fabrication capacity, yet SK Hynix holds the highest HBM production capacity. Micron has the smallest HBM capacity, with total capacity only about one-third of Samsung's. In the current memory super-cycle, production capacity determines not only whether a company can create a cost advantage but also affects its bargaining power and risk resilience.

Moving from the HBM3 to the HBM4 era, chip manufacturing costs are rising significantly, primarily because the logic base dies must switch to advanced logic wafer processes. Memory manufacturers cannot produce these internally and must outsource to TSMC or its affiliate, Global Unichip (GUC), causing wafer foundry costs to increase several-fold. Additionally, because HBM4 chips involve higher stacking levels, yield loss is also greater.

In this context, Micron, with its lower shipment volume, may face greater yield fluctuations and shipment instability. Furthermore, because Samsung and SK Hynix have larger shipment volumes, they can amortize high fixed costs. Conversely, Micron may need to further raise prices on top of its already relatively high selling prices. Moreover, since all these manufacturers must outsource orders to TSMC, Samsung and SK Hynix, with their larger order scales, will gain stronger bargaining power, continuing to overwhelm Micron on costs.

Regarding production capacity, major manufacturers are currently expanding. Given that SK Hynix's dedicated HBM production lines already account for a significant portion and Micron's output is low, the only variable now is whether Samsung will convert its DRAM lines to HBM production in the short term to surpass SK Hynix in capacity. If Samsung makes this "painful" transition, it could potentially crush SK Hynix in terms of cost.

Capital Efficiency: Micron's High Gross Margin Relies on Technological Advantage

However, in terms of capital efficiency, the performance of these three companies is a different story. Capital efficiency measures the return on every dollar invested, and Micron's performance is most noteworthy in this regard. Although the analysis above suggests Micron has the lowest cost advantage, the company has fortunately taken the opposite approach by focusing on high-margin orders. Financial results released on March 16, 2026, show that in the first quarter of fiscal year 2026, the gross margin of Micron's Cloud and Networking Business Unit (CNBU), which includes HBM, reached a staggering 66%.

This is primarily because Micron's HBM3E power consumption is approximately 30% lower than its competitors, with less heat generation. This is highly attractive to major players like NVIDIA, who urgently need to mitigate data center heat issues and ensure stable system performance, thus creating a market even at higher prices.

However, Micron's high premium is built on its technological lead. Given the progress of Samsung and SK Hynix in the 1̳ process, HBM power consumption for these two companies is expected to decrease further. If Micron cannot maintain its advantage over competitors, its high-margin status will be unsustainable.

Although these three giants have all risen significantly since 2026, many analyses suggest that there is still clear room for growth. According to Yahoo Finance data, as of the Korean stock market close on March 17, Samsung's price-to-book (P/B) ratio was only 2.97, lower than SK Hynix's 6.73 and Micron's 8.46. This indicates that the market is only willing to pay a 2.97x premium for Samsung's assets, proving that Samsung is significantly undervalued compared to its competitors.

From a price-to-earnings (P/E) ratio perspective, Micron's P/E (TTM) stands at 42, while SK Hynix is at 19.28 and Samsung is at 20.68. This suggests that the market is willing to pay the highest price for Micron's future earnings, while the willingness to pay for Samsung and SK Hynix is lower.

Micron's P/E ratio is close to growth stock levels, as the market is optimistic about the company's profit growth over the coming quarters. However, this also means that if Micron's performance fails to meet market expectations, it could suffer a sharp decline. SK Hynix's P/E of 19x suggests that its earnings are already relatively stable and predictable, primarily because the company has become the main supplier of HBM to NVIDIA, leaving less room for explosive profit growth compared to Micron.

Combining P/B and P/E ratios, Samsung appears to be the most clearly undervalued. The company possesses the world's largest cluster of wafer fabs, yet the future returns on these assets are significantly underestimated, and the stock price does not reflect market expectations for future earnings. As Samsung's massive wafer capacity is unleashed, the company is expected to see profit growth and a valuation rerating; thus, the current stock price still has ample room for growth.

Within the category of memory stocks, Micron's stock price is currently overvalued by the market compared to Samsung. However, if Micron is redefined as an AI computing infrastructure stock, its 42x P/E would be lower than its peers. This shift in valuation logic allows Micron to command a higher premium from the AI wave than its competitors, primarily because Micron's focus on HBM products is far greater than that of Samsung and SK Hynix. Furthermore, as the only domestic U.S. HBM manufacturer, Micron will also benefit from the CHIPS Act, and its stock price incorporates a geopolitical hedge premium.

Compared to the two aforementioned companies, SK Hynix is undoubtedly a steady performer. Although the likelihood of explosive growth is lower, it can serve as a cornerstone in an investment portfolio.

Globally, regardless of where the memory supercycle first emerges, Taiwan will undoubtedly be among the ultimate beneficiaries. Taiwan's semiconductor industry is mature, offering everything from R&D to assembly and testing; for supply chain synergy, many chip companies choose to establish operations in Taiwan. The Taiwan stock market supply chain almost covers the entire chip production process.

AI Chip Foundry Giants

TSMC (2330) is arguably one of the biggest winners of the memory supercycle, as it does not need to compete directly with the three HBM giants and instead benefits from the expansion of the HBM market. Whether for SK Hynix, Samsung, or Micron, their HBM4 base dies and final CoWoS packaging are almost impossible to complete without TSMC.

Global Unichip (3443), a subsidiary of TSMC, is responsible for integrating HBM interface designs into TSMC's manufacturing processes, making it an indispensable link in the supply chain.

Powertech Technology (6239) is a global leader in memory assembly and testing and a long-term partner of Micron. Powertech focuses on FOPLP technology as an alternative to TSMC's CoWoS, allowing it to benefit from TSMC's spillover orders.

Beneficiaries of Memory Giants Shifting Focus from Traditional DRAM

As SK Hynix, Samsung, and Micron shift their focus to higher-margin HBM chips, a severe supply gap has emerged for traditional DDR4/DDR5, leading to price increases that even exceed those of HBM. Nanya Technology (2408) is Taiwan's DRAM leader, while Winbond (2344) focuses on niche DRAM; both will benefit significantly from this cycle.

In addition to DRAM manufacturers, some module makers such as ADATA (3260), which stockpiled DRAM modules before the price surge, and Phison (8299), which stockpiled NAND Flash, are also beneficiaries.

The "Pick-and-Shovel" Plays of the Memory Industry

As the three HBM giants expand production, their demand for high-precision equipment and advanced process consumables has grown substantially. Allring Tech (6187) provides key dispensing and bonding equipment for HBM packaging; GPM (6640) and C Sun (2467) provide the necessary pressing and heat treatment equipment; and Kinik (1560) provides the diamond disks essential for the advanced 1γ process—all of which will benefit.