Woofun AI data shows that US stock futures rose broadly during pre-market trading on July 21st, driven by a surge in fiber optic concept equities. Marvell Technology (MRVL) led the sector with a 6.24% increase, while Coherent Corp. (COHR) and Lumentum Holdings (LITE) gained 5.23% and 5.15% respectively. Applied Optoelectronics (AAOI) rose 5.07%, Ciena Corporation (CIEN) climbed 3.94%, and the PureFunds ISE Cyber Security ETF (HACK) advanced 3.81%.