Optical Communication Stocks Extend Gains; Qingshan Paper, Tianyang New Materials Hit 2-Day Limit-Up

The breadth of the move — beyond the two limit-up names to Cambridge Technology, Huafeng Technology, Changxin Bochuang and Dongshan Precision — suggests the optical communication theme is being traded as a sector rather than on single-stock catalysts. That matters because it implies positioning is building on the narrative itself, which tends to amplify both momentum and reversal risk. What's worth watching is whether the second-day limit-ups hold and whether follow-through broadens further or narrows to a handful of names, since a narrowing rally would signal the theme is losing fresh participation.