Key points
- Two of the five sell mostly DRAM, two sell only NAND
- Chips generated nearly all Samsung's Q2 operating profit
- All five peaked in June and trade below those highs
- Only three have a US exchange listing
Micron (MU), SK Hynix (SKHY), Samsung Electronics, Sandisk (SNDK), and Kioxia all sell memory chips, but they earn their money from different parts of the market.
Micron and SK Hynix get most of their revenue from DRAM, the working memory processors use during calculations. That includes high-bandwidth memory, or HBM, which stacks DRAM in layers to deliver data quickly to AI processors. Sandisk and Kioxia focus on NAND flash, which stores data even when the power is off. Samsung makes both, alongside phones, TVs, and other electronics, but its semiconductor division generated nearly all its operating profit in the second quarter.
All five stocks reached their peak closing prices between June 18 and June 25, 2026. At the September 22 closes (September 18 for Kioxia), they were between 9.7% and 49.8% below those highs. Micron's fiscal fourth-quarter report on September 30 is the next scheduled earnings release from the group.
Our explainers cover what HBM is and who makes NAND flash.
The figures below cover each company's entire business and different reporting periods. Samsung's totals include its non-memory businesses.
| Company | Main memory | Latest reported quarter | Revenue | Operating profit | Close vs. peak close |
|---|---|---|---|---|---|
| Micron (MU) | DRAM (76% of revenue, including HBM); NAND | Fiscal Q3, ended May 28 | $41.5B | $33.3B | 9.7% below |
| SK Hynix (Seoul: 000660; US: SKHY) | DRAM, including HBM, and NAND | Q2, April to June | about $58.5B | about $44.7B | 36.9% below |
| Samsung Electronics (Seoul: 005930) | DRAM, including HBM, and NAND, plus phones and TVs | Q2, April to June | about $126.5B | about $66.0B | 23.4% below |
| Sandisk (SNDK) | NAND only | Fiscal Q4, ended July 3 | $9.0B | $7.0B | 19.2% below |
| Kioxia (Tokyo: 285A) | NAND only | Fiscal Q1, April to June | about $11.2B | about $8.1B | 49.8% below |
Revenue and operating profit use each company's reported basis: US GAAP for Micron and Sandisk, K-IFRS for SK Hynix and Samsung, and IFRS for Kioxia. Won and yen figures are converted at 1,355.5 won and 157.45 yen to the dollar, derived from Naver Finance's September 22 rates. Closes are from September 22, except Kioxia's, which is September 18, the last session before three Japanese holidays. SK Hynix is measured on its Seoul shares.
Micron: US-listed exposure to DRAM
Micron's fiscal third quarter brought $41.5 billion of revenue, with DRAM at 76% and NAND at 24%, and GAAP operating income of $33.3 billion, according to its earnings release. Micron does not report HBM revenue separately. The company said it had already shipped more than $1 billion of HBM4 and guided fiscal fourth-quarter revenue to $50.0 billion, plus or minus $1 billion. Micron trades on the Nasdaq, closed at $1,096.16 on September 22, and is up 284% this year.
SK Hynix: a US listing at a premium
SK Hynix reported second-quarter revenue of 79.3 trillion won ($58.5B) and operating profit of 60.5 trillion won ($44.7B), a 76% operating margin, according to a filing with US regulators. Its net profit of 93.9 trillion won was larger than revenue because of about 53.2 trillion won of gains on the value of financial instruments and 10.0 trillion won of dividend income. DRAM was 77.3% of revenue in the first quarter, the latest split SK Hynix has disclosed. The company began mass shipments of HBM4 in the second quarter and has signed long-term supply agreements with about 10 customers.
US investors can buy SK Hynix through SKHY, American depositary shares on the Nasdaq that priced at $149 on July 9. Ten SKHY shares represent one Seoul share. Using the September 22 closing prices and the exchange rate above, SKHY traded about 44% above the value of the Seoul shares it represents. The comparison uses closing prices recorded at different times. The Seoul shares closed at 1,841,000 won ($1,358) and are up 183% this year. Our guide covers how to buy SKHY.
Samsung: memory inside a broader business
Samsung reported second-quarter revenue of 171.5 trillion won ($126.5B) and operating profit of 89.5 trillion won ($66.0B), according to its results release. Memory brought in 120.8 trillion won ($89.1B), about 70% of revenue, and the chip division earned 89.2 trillion won of the 89.5 trillion won total. The division that makes phones, TVs, and appliances posted an operating loss of 0.8 trillion won. Samsung says its HBM4 is designed for Nvidia's Vera Rubin platform.
Samsung has no US exchange listing. Samsung trades in Seoul, where it closed at 277,500 won ($205) and is up 131% this year, and as global depositary receipts in London, each representing 25 common shares. A thinly traded over-the-counter line, SSNLF, also exists. US investors can also get indirect exposure through Korea funds such as the iShares MSCI South Korea ETF (EWY), as our guide to buying Korean stocks explains.
Sandisk: NAND production shared with Kioxia
Sandisk's fiscal fourth quarter brought $9.0 billion of revenue and $7.0 billion of GAAP operating income, with $3.0 billion from data-center customers, according to its earnings release. Sandisk guided fiscal first-quarter revenue to $10.3 billion to $10.8 billion. Western Digital spun the company off in February 2025. Sandisk gets its flash wafers from joint-venture fabs in Japan operated with Kioxia. The partners divide output about evenly, and their joint-venture agreements extend through 2034. Sandisk trades on the Nasdaq, closed at $1,887.04 on September 22, and is up 695% this year.
Kioxia: Sandisk's partner in Japan
Kioxia's fiscal first quarter brought 1.77 trillion yen ($11.2B) of revenue and 1.27 trillion yen ($8.1B) of operating profit under IFRS, according to its results filing. Kioxia guided second-quarter revenue to 2.39 trillion yen. Bain Capital funds and Toshiba are its largest shareholders, and SK Hynix holds convertible bonds in a Bain vehicle that owns Kioxia shares.
Kioxia's primary listing is in Tokyo, where it closed at 54,570 yen ($347) on September 18, up 423% this year. The company said in May that it is preparing to list American depositary shares in the US, with timing and exchange undecided. A 3-for-1 stock split takes effect October 1, 2026, which will cut the per-share price to about a third without changing the company's value.
Micron reports on September 30, covering June through August. Its results will offer the next update on memory demand and pricing. The distinction to watch is how DRAM and NAND perform, because the five companies have different exposure to each.
