[AI hardware and semiconductor sectors fell sharply. Lumentum fell more than 11%] On November 4, the AI ​​hardware and semiconductor sectors of the US stock market collectively pulled back, and the Philadelphia Semiconductor Index fell more than 3.8%. Optical communications, storage and equipment giants led the decline, among which Lumentum fell by more than 11%, triple long semiconductor ETF (SOXL) fell by more than 11%, Coherent fell by more than 8%, Marvell Technology fell by more than 8%, SanDisk fell by more than 7%, Seagate Technology fell by more than 7%, Western Digital fell by more than 6%, Micron Technology fell by more than 5%, Intel fell by more than 5%, SK Hynix fell by more than 4%, Arm fell by more than 4%, and ASML fell by nearly 4%. Computing power leaders Nvidia, TSMC, and Broadcom all fell by more than 2%. Qualcomm bucked the trend and rose more than 1%.