NAND Flash

NAND flash is non-volatile memory that stores data without power, holding each bit by trapping charge in a cell, with modern devices stacking those cells in hundreds of 3D layers. It is the storage inside SSDs, smartphones, and memory cards, and a handful of makers, including Samsung, SK Hynix, Kioxia, Micron, and China’s YMTC, produce nearly all of it.

What is NAND flash?

NAND flash stores each bit by trapping electric charge in a memory cell, either in a floating gate or a charge-trap layer, and because the charge stays put when the power is off, the data is non-volatile. That is the opposite of DRAM, which is fast but loses its contents the moment power is cut. The trade-off is speed: NAND is slower to read and write than DRAM, but far cheaper per bit and able to hold data for years, which is why it became the storage layer of computing. To raise density without shrinking cells further, makers stopped going flatter and started going taller: modern 3D NAND stacks cells vertically, and the leading edge has passed 290 layers, with China’s Yangtze Memory shipping a fifth-generation 294-layer 3D NAND built on its Xtacking wafer-bonding architecture (Tom’s Hardware). Capacity per chip is also raised by storing more bits per cell, from one bit (SLC) up through TLC (three bits) and QLC (four bits), trading endurance for density. Production is concentrated in a handful of firms: Samsung, SK Hynix and its Solidigm unit, Kioxia, Micron, SanDisk, and YMTC.

How is NAND flash used in thematic investing?

NAND is one of the two pillars, alongside DRAM, of the Asia memory semiconductor concept, and it is central to the China memory and storage thesis. The AI build-out has tightened NAND supply because data centers buy enterprise SSDs by the rack, and the NAND market reached a record of about $46 billion in the first quarter of 2026 (Counterpoint via DIGITIMES). TrendForce projects NAND revenue to rise 112% to $147.3 billion in 2026 (TrendForce). For investors, NAND is where China has closed the most ground: YMTC’s share roughly doubled to about 13% in the first quarter of 2026, level with Micron and SanDisk, the fastest growth of any maker.

“YMTC has rapidly risen to become the market’s most impressive performer.”

— Counterpoint Research, Q1 2026 NAND market report (DIGITIMES)

That rise is why a storage-module maker like Longsys, which packages NAND into SSDs and memory cards, is so leveraged to NAND pricing, and why NAND share is one of the most-watched variables in any China memory thesis.

Related terms & concepts

FAQ

What is NAND flash?

NAND flash is non-volatile memory: it keeps stored data when the power is off. It holds each bit by trapping electric charge in a memory cell, and modern chips stack those cells vertically in hundreds of layers (3D NAND) to raise density. It is the storage technology inside SSDs, smartphones, USB drives, and memory cards, and the AI build-out has tightened its supply, with the NAND market reaching a record about $46 billion in Q1 2026 (Counterpoint via DIGITIMES).

How is NAND flash different from DRAM?

They do different jobs. NAND flash is non-volatile storage: slower, cheaper per bit, and it keeps data without power, so SSDs are built from it. DRAM is volatile working memory: faster but it loses its contents when power is cut, so it holds what a processor is actively using. A server needs both, and the AI boom is straining both at once, with TrendForce projecting NAND revenue up 112% to $147.3 billion and DRAM up 144% to $404.3 billion in 2026 (TrendForce).

Who makes NAND flash?

A small group dominates: Samsung, SK Hynix (with Solidigm), Kioxia, Micron, and SanDisk, plus China's Yangtze Memory (YMTC). YMTC has risen fastest, reaching about 13% of the market in Q1 2026, level with Micron and SanDisk and behind only Samsung (29%), SK Hynix (18%), and Kioxia (14%) (Counterpoint via DIGITIMES).

Sources & references

  1. YMTC Revenue Surges as NAND Flash Market Hits Record in Q1 2026 (Counterpoint Research) · Counterpoint Research / DIGITIMES, 2026-06-03
  2. AI Architecture Evolution Set to Drive Memory Market Revenue to a New Peak in 2027 · TrendForce, 2026-01-22
  3. Chinese Chipmaker Ships Record-Breaking Chips: YMTC Begins Shipping 5th-Gen 3D TLC NAND · Tom's Hardware, 2025-01-30