Micron Technology shares fell roughly 6% in early trading on July 13 after SK Hynix, the South Korean memory giant, posted a second-quarter profit forecast that landed 8% below analyst consensus. The miss triggered a cascade across the entire memory and storage sector, dragging SanDisk and Western Digital down by similar margins and sending SK Hynix itself into a record 15% single-day plunge.
The culprit behind the guidance shortfall: delayed shipments of high-bandwidth memory (HBM4), the specialized chips that power the most advanced AI training clusters.
The damage report
SK Hynix’s 15% drop marked its steepest single-day decline on record, a particularly brutal milestone given the company had only recently debuted on the Nasdaq. The selloff was not contained to individual names. The Roundhill Memory ETF, which tracks a basket of semiconductor and storage companies, fell 9% as broad-based selling swept through the sector.
Seagate dropped 4%, a comparatively gentle decline that probably felt like a win for shareholders watching the rest of the sector implode.
