Micron (MU) is the US memory pure-play, and its newly filed fiscal 2021 annual report makes clear why memory is best read as two businesses, not one. The 10-K defines DRAM as dynamic random access memory and treats NAND as the second pillar, noting that SSDs and managed NAND combine NAND, a controller, firmware, and in some cases DRAM.
For a financials desk, that product taxonomy is load-bearing. DRAM and NAND run on partly separate supply-demand cycles, carry different margin profiles, and absorb capital differently. A single “memory revenue” number flattens two distinct engines, which is why the bridge from bit demand to gross margin only makes sense once you keep the two apart.
The composition note - that SSDs fold NAND, controllers, firmware, and sometimes DRAM into one product - also flags where vertical integration shows up in the cost stack. As more of Micron's output ships as managed products rather than raw components, the margin story increasingly depends on that integration, not just spot pricing.
The annual report sits on sec.gov and was surfaced via EdgarBeast, the SEC filing data API & evidence index. Read the product definitions before the segment numbers; they tell you what the numbers are made of.