US memory chip index jumps 9.2% as Nasdaq 100 gains 2.3%

The dispersion is the story here: memory and AI-infrastructure names like CoreWeave and Micron rallied far harder than the broad tech sector, while Microsoft and Amazon slipped, suggesting the bid is concentrated in the compute and memory supply chain rather than megacap platforms. That gap matters because it signals where conviction is clustering within AI exposure. Whether this memory-led outperformance holds, or proves a single-session rotation, is the open question.