US stocks open mixed: Philadelphia Semiconductor Index falls nearly 2%, memory chip stocks slide

The split between a firmer Dow and a weaker semiconductor complex suggests the selling is concentrated in memory and storage names rather than broad risk-off, with CoreWeave's co-founder share sale adding a separate, company-specific drag on AI-adjacent equities. Memory pricing and inventory cycles remain the swing factor for this group, so whether the weakness stays contained to that niche or spreads into the wider chip complex is the open question. The divergence between megacap strength in Tesla and Apple and softness in the Nasdaq 100 is worth tracking as a signal of where positioning is rotating.