✦ AI Storage and the NAND TurnThin moat

SK hynix (SKHY) — the future bets

A boom improves everybody's economics in NAND; it does not fix a market with five participants instead of three.

NAND was 21.3% of sales in 2025 and 22.0% in the first quarter of 2026, against DRAM's 77.1% and 77.3%1. Until this year one half of the company was in a supercycle and the other was having an ordinary year in a difficult industry. In the second quarter of 2026 NAND revenue rose 364% to ₩22.0 trillion5 and reached 27.7% of sales6.

NAND flash share of sales (%)21.3%202522.0%Q1 202627.7%Q2 2026SK hynix prospectus and semi-annual report
The first quarter in which the smaller half grew faster.

The bet being placed is that this changes. AI systems consume enormous quantities of data, and that data has to sit somewhere fast enough to feed the accelerators — which pulls demand toward high-performance enterprise SSDs rather than the consumer NAND that has driven the market historically. SK hynix developed the world's first 321-layer QLC NAND and is building out high-capacity enterprise SSD around it2, and Solidigm's enterprise SSD franchise, acquired from Intel for $8.8 billion in total3, is aimed squarely at that customer.

The strategic logic is sound. Enterprise SSD is the most differentiated, least commoditised part of NAND, and it is bought by exactly the customers already buying HBM.

The structural problem does not go away. NAND has five meaningful participants against DRAM's three4, and a market with five participants prices differently no matter what the demand does. A boom improves everybody's economics; it does not fix the industry's coordination problem.

The measure is NAND operating margin through a full cycle rather than in a good quarter. If it converges toward DRAM's, the acquisition bought something structural. If it does not, it bought scale in a worse business.

Moat trajectory: Widening

NAND revenue rose 364% in the June 2026 quarter against DRAM's 233%, reaching 27.7% of sales. The market still has five participants.

The number that tests this moat
Moat Explorer calc
NAND share of sales, latest quarter
27.7% in Q2 2026, from 22.0% in Q1 and 21.3% in 2025

The first quarter in which NAND outgrew DRAM (+364% against +233%). Holding above a quarter of sales would show the AI-storage turn is more than a price spike.

How it's calculated: 21,959,898 / 79,318,746.
Source: SK hynix semi-annual business report, January-June 2026 (Form 6-K, August 2026) (Moat Explorer calc) ↗
References
  1. ReportedNAND was 21.3% of sales in 2025 and 22.0% in the first quarter of 2026, against DRAM's 77.1% and 77.3%.
    SK hynix Inc., Form 424B4 prospectus — risk factors and the offering (SEC, CIK 2120882). 'A substantial portion of our sales is attributable to a limited number of customers located in the United States and China. Our two largest customers represented 14.8% and 12.4%, respectively, of our total revenue in the first quarter of 2026 and our largest customer represented 23.9% of our total revenue in 2025.' DRAM products were 77.3% of total sales in Q1 2026 and 77.1% in 2025; NAND flash 22.0% and 21.3%. NAND mass production is transitioning from 176-layer technology to 238- and 321-layer technologies. The offering was 177,900,000 ADSs at US$149.00 each, representing 17,790,000 common shares against 712,702,365 outstanding, each ADS one-tenth of a share; Baillie Gifford Overseas, funds managed by Coatue Management and Situational Awareness Partners indicated a non-binding interest of up to US$7 billion. — FY2025 and Q1 2026 · publ. 2026-07-10 · source ↗
  2. ReportedSK hynix developed the world's first 321-layer QLC NAND and is expanding high-capacity enterprise SSD around it with Solidigm.
    SK hynix Inc., semi-annual business report for the six months to 30 June 2026 (SEC Form 6-K, 18 August 2026) — 'The Company determines supply volumes and prices on a monthly and quarterly basis by mutual agreement with major customers, and there is no order backlog based on long term supply contracts.' Total equity W 262,693,228 million at 30 June 2026 against W 120,666,751 million at 31 December 2025; cash and cash equivalents, short-term financial instruments and short-term investment assets W 87,957,923 million against W 34,942,253 million; total borrowings W 18,586,634 million against W 22,247,905 million; debt-to-equity 32.80%, net borrowing ratio not disclosed because it is negative. For the six months to 30 June 2026, revenues of W 17,608,702 million (13.35%) and W 17,187,421 million (13.03%) were derived from external Customers A and B respectively; for the six months to 30 June 2025, W 10,890,639 million (27.31%) came from Customer A. IDC market share: DRAM 29.9% in 2023, 33.4% in 2024, 34.8% in 2025 and 29.1% in Q1 2026; NAND 19.6%, 21.4%, 20.9% and 18.5%. Gartner's world DRAM market: US$78.7bn in 2022 (-15.4%), US$49.9bn in 2023 (-36.5%), US$91.6bn in 2024 (+82.7%) and US$146.9bn in 2025 (+60.0%). Announced investments include approximately W 15 trillion for M15X in Cheongju, approximately W 19 trillion for the P&T7 advanced packaging plant and W 21,608.1 billion for Yongin, against long-term plans of roughly W 600 trillion for the Yongin cluster and W 100 trillion for Cheongju. The company developed the world's first 321-layer QLC NAND. China's State Administration for Market Regulation cleared the Intel NAND acquisition conditionally, obliging the group to maintain a reasonable pricing policy, increase production and support the entry of third-party competitors into the Chinese eSSD market for five years from December 2021. — six months to 30 June 2026 · publ. 2026-08-18 · source ↗
  3. ReportedIntel's NAND business cost US$8.8bn in total — US$6.6bn in December 2021 and US$2.2bn in March 2025.
    SK hynix Inc., Form 424B4 prospectus for its Nasdaq offering (SEC, CIK 2120882) — FY2025 revenue W 97,147bn, cost of sales W 38,456bn, gross profit W 58,691bn, S&A W 5,019bn, R&D W 6,466bn and profit for the year W 42,948bn, against FY2024 revenue W 66,193bn / profit W 19,797bn and FY2023 revenue W 32,766bn / cost of sales W 33,299bn / gross loss W 533bn / loss for the year W 9,138bn; Q1 2026 revenue W 52,576bn, gross profit W 41,679bn, profit W 40,346bn. IDC market shares for Q1 2026: second in DRAM at 29.1%, first in HBM at 56.4%, second in NAND at 18.5%, with the three DRAM producers together above 90% of revenue. DRAM products were 77.1% of total sales in 2025 and 77.3% in Q1 2026; NAND 21.3% and 22.0%. Competitors named: Samsung Electronics, Micron Technology and CXMT in DRAM; Samsung Electronics, Kioxia, Micron Technology and Sandisk in NAND; competitive factors listed as 'pricing; manufacturing costs, yields and product availability; product performance, quality and reliability'. First to develop HBM using TSV packaging, commercialised HBM3E in 2024 and developed HBM4 in 2025; HBM carried a per-gigabyte price premium of more than five times traditional DRAM in 2025. M15X cleanroom opened October 2025 with wafer input from Q1 2026; Yongin construction began February 2025 with the first fab's phase-one cleanroom expected Q1 2027; an advanced packaging plant (P&T7) is under construction in Cheongju and one is planned in Indiana for the second half of 2028. Intel's NAND business cost US$6.6bn in December 2021 plus US$2.2bn in March 2025, operated as Solidigm; NAND mass production is transitioning from 176-layer to 238- and 321-layer technologies. Gartner forecasts DRAM revenue of US$143bn in 2025 rising to US$401bn in 2027, HBM US$33bn to US$86bn and NAND US$68bn to US$341bn. A substantial portion of sales is attributable to a limited number of customers located in the United States and China; the two largest were 14.8% and 12.4% of revenue in Q1 2026 and the largest was 23.9% of revenue in 2025. The offering was 177,900,000 ADSs at US$149.00, each ADS one-tenth of a common share, representing 17,790,000 shares against 712,702,365 outstanding; Baillie Gifford, Coatue and Situational Awareness Partners indicated non-binding interest of up to US$7bn. — FY2023-FY2025 and Q1 2026 · publ. 2026-07-10 · source ↗
  4. ReportedSK hynix's NAND competitor list has five participants against DRAM's three.
    SK hynix Inc., Form 424B4 prospectus for its Nasdaq offering (SEC, CIK 2120882) — FY2025 revenue W 97,147bn, cost of sales W 38,456bn, gross profit W 58,691bn, S&A W 5,019bn, R&D W 6,466bn and profit for the year W 42,948bn, against FY2024 revenue W 66,193bn / profit W 19,797bn and FY2023 revenue W 32,766bn / cost of sales W 33,299bn / gross loss W 533bn / loss for the year W 9,138bn; Q1 2026 revenue W 52,576bn, gross profit W 41,679bn, profit W 40,346bn. IDC market shares for Q1 2026: second in DRAM at 29.1%, first in HBM at 56.4%, second in NAND at 18.5%, with the three DRAM producers together above 90% of revenue. DRAM products were 77.1% of total sales in 2025 and 77.3% in Q1 2026; NAND 21.3% and 22.0%. Competitors named: Samsung Electronics, Micron Technology and CXMT in DRAM; Samsung Electronics, Kioxia, Micron Technology and Sandisk in NAND; competitive factors listed as 'pricing; manufacturing costs, yields and product availability; product performance, quality and reliability'. First to develop HBM using TSV packaging, commercialised HBM3E in 2024 and developed HBM4 in 2025; HBM carried a per-gigabyte price premium of more than five times traditional DRAM in 2025. M15X cleanroom opened October 2025 with wafer input from Q1 2026; Yongin construction began February 2025 with the first fab's phase-one cleanroom expected Q1 2027; an advanced packaging plant (P&T7) is under construction in Cheongju and one is planned in Indiana for the second half of 2028. Intel's NAND business cost US$6.6bn in December 2021 plus US$2.2bn in March 2025, operated as Solidigm; NAND mass production is transitioning from 176-layer to 238- and 321-layer technologies. Gartner forecasts DRAM revenue of US$143bn in 2025 rising to US$401bn in 2027, HBM US$33bn to US$86bn and NAND US$68bn to US$341bn. A substantial portion of sales is attributable to a limited number of customers located in the United States and China; the two largest were 14.8% and 12.4% of revenue in Q1 2026 and the largest was 23.9% of revenue in 2025. The offering was 177,900,000 ADSs at US$149.00, each ADS one-tenth of a common share, representing 17,790,000 shares against 712,702,365 outstanding; Baillie Gifford, Coatue and Situational Awareness Partners indicated non-binding interest of up to US$7bn. — FY2023-FY2025 and Q1 2026 · publ. 2026-07-10 · source ↗
  5. ReportedIn the second quarter of 2026 NAND revenue rose 364% to ₩22.0 trillion.
    SK hynix Inc., semi-annual business report for the six months to 30 June 2026 (SEC Form 6-K, 18 August 2026) — 'The Company determines supply volumes and prices on a monthly and quarterly basis by mutual agreement with major customers, and there is no order backlog based on long term supply contracts.' Total equity W 262,693,228 million at 30 June 2026 against W 120,666,751 million at 31 December 2025; cash and cash equivalents, short-term financial instruments and short-term investment assets W 87,957,923 million against W 34,942,253 million; total borrowings W 18,586,634 million against W 22,247,905 million; debt-to-equity 32.80%, net borrowing ratio not disclosed because it is negative. For the six months to 30 June 2026, revenues of W 17,608,702 million (13.35%) and W 17,187,421 million (13.03%) were derived from external Customers A and B respectively; for the six months to 30 June 2025, W 10,890,639 million (27.31%) came from Customer A. IDC market share: DRAM 29.9% in 2023, 33.4% in 2024, 34.8% in 2025 and 29.1% in Q1 2026; NAND 19.6%, 21.4%, 20.9% and 18.5%. Gartner's world DRAM market: US$78.7bn in 2022 (-15.4%), US$49.9bn in 2023 (-36.5%), US$91.6bn in 2024 (+82.7%) and US$146.9bn in 2025 (+60.0%). Announced investments include approximately W 15 trillion for M15X in Cheongju, approximately W 19 trillion for the P&T7 advanced packaging plant and W 21,608.1 billion for Yongin, against long-term plans of roughly W 600 trillion for the Yongin cluster and W 100 trillion for Cheongju. The company developed the world's first 321-layer QLC NAND. China's State Administration for Market Regulation cleared the Intel NAND acquisition conditionally, obliging the group to maintain a reasonable pricing policy, increase production and support the entry of third-party competitors into the Chinese eSSD market for five years from December 2021. — six months to 30 June 2026 · publ. 2026-08-18 · source ↗
  6. Moat Explorer calcNAND reached 27.7% of sales in the second quarter of 2026.
    Moat Explorer calculation from SK hynix's semi-annual business report, January-June 2026: Q2 2026 revenue by product DRAM W56,982,743M, NAND flash W21,959,898M, others W376,105M of W79,318,746M (Q2 2025: W17,123,990M, W4,727,806M of W22,231,952M) - shares and growth rates as stated. — Q2 2026 · publ. 2026-08-14 · source ↗
    Method: 21,959,898 / 79,318,746.
Sources
Generated September 23, 2026