Optics stocks rallied on Monday, driven by a United Daily News report detailing severe undersupply in indium phosphide (InP) substrates and epitaxial wafers. Q4 InP substrate prices are expected to increase by over 10%, marking the largest increase on record. AXT (AXTI), a leading InP substrate producer, saw its shares climb 13.71% intraday to $92.83, extending its year-to-date gain to 399.33%. Coherent (COHR) rose 8.12%, and Lumentum (LITE) gained 6.79%. 英伟达 (NVIDIA) also disclosed a $3.07 billion stake in Coherent, representing nearly 5% of its 13F portfolio.