The memory chip sector just had the kind of week that makes portfolio managers reach for the antacids. Micron and Sandisk each dropped more than 6%, Western Digital fell over 7%, and the Philadelphia Semiconductor Index (SOXX) posted a 7.9% weekly decline, its worst performance since April 2025.
The culprit? Growing fears that surging prices for high-bandwidth memory, the specialized chips feeding the AI boom, are starting to squeeze the margins of downstream tech companies that actually have to buy the stuff. Apple’s name came up more than once in that conversation.
From trillion-dollar highs to a rough landing
Micron’s stock surged over 300% year-to-date before this week’s selloff. Sandisk posted gains in the hundreds of percent. Both SK Hynix and Micron crossed the $1 trillion market cap threshold back in May, powered almost entirely by insatiable AI-driven memory demand.
For stretches of this year, memory stocks were actually outperforming Nvidia. Intraday swings on the SOXX reached as high as 3.8% during the week of June 26-27.
