Lumentum is selling off today, tracking a broader decline across the optical equipment sector that has seen peers like Coherent, Fabrinet, and Ciena also move significantly lower. This downward pressure follows reports that Microsoft is actively pushing back against a proposed U.S. ban on Chinese optical transceivers, a policy shift that had previously fueled expectations of a windfall for domestic suppliers. While the company remains tied to the regulatory timeline of its proposed acquisition by Marvell, the stock is currently reacting to this cooling sentiment regarding the potential protectionist tailwinds for U.S.-based optical component manufacturers.