AI tech selloff: S&P 500 falls 4.36%, Nasdaq drops 5.52%

In the early hours of November 6 (Beijing time), U.S. equities sold off sharply, with the S&P 500 closing down 4.36% and the Nasdaq Composite collapsing 5.52%. The initial wave of selling was centered on AI technology hardware, then spread rapidly outward. U.S. technology shares, innovative drug makers, AI software applications and even consumer-related names all came under pressure. Selling hit semiconductors, biopharma, power equipment, software and media, communications equipment, autos and defense; even cyclical areas such as retail and digital entertainment were dragged down. Across the broader market, only a handful of defensive areas finished higher, including water utilities and residential REITs.

At the individual-stock level, core U.S. holdings heavily weighted by QDII funds were among the hardest hit. Multiple large-cap technology names posted double-digit declines, and the damage extended from hardware toward software technology, innovative drugs and AI software. Micron Technology, a popular position among QDII managers, fell 17.46% at the close, and SanDisk, held by several QDII products, plunged 22.26%. Lumentum dropped 18.68%, Western Digital fell 17.35%, and Advanced Micro Devices closed down 17.26%. AI image-enhancing leader Figma declined 16.67%, e-commerce SaaS giant Shopify and semiconductor-equipment maker Lam Research each tumbled 16.36%, Seagate Technology lost 16.25%, STMicroelectronics fell 12.43%, TSMC dropped 11.03%, and Intel closed down (the report's individual-stock data is truncated cut off at Intel's decline, so the percentage cannot be fully confirmed from this material).