Sandisk makes NAND flash memory, the storage technology behind solid state drives, memory cards and USB drives. The company was spun off from Western Digital and relisted as an independent stock, separating its flash memory business from Western Digital's traditional hard disk drive operations. Flash memory pricing is notoriously cyclical, swinging between periods of oversupply that crush margins and shortages that lift them, since manufacturers must commit to expensive fabrication capacity years before knowing what demand will look like. Sandisk competes with Samsung, SK Hynix, Micron and Kioxia in a market with heavy capital requirements and only a few global suppliers.