Micron and SanDisk are the NAND/DRAM memory names in this trio. Western Digital is essentially a pure hard-disk-drive (HDD) company after spinning off and divesting its remaining stake in SanDisk. That separation, completed in February 2025, means factors pressuring memory pricing hit Micron and SanDisk but largely spare Western Digital's drive business. thinkstock The split is striking because these three names traded as one theme for much of the past year. Micron stock is up 265% year to date (YTD), and S ...