Data storage companies reported strong quarterly results and provided robust future guidance that nonetheless fell short of the market's lofty expectations. This triggered a significant sell-off in the memory and storage sector, with major players like Western Digital, Sandisk, Micron, and SK Hynix seeing notable declines. The negative sentiment comes after a period of massive year-to-date gains for these stocks, leading to an expectations reset by investors despite continued strong demand from the AI industry.