Silicon Motion designs and sells NAND flash controller chips — the semiconductors that manage how data is stored and retrieved on NAND flash memory. Without a controller, raw NAND flash is unusable, and Silicon Motion sits between NAND flash makers and the end products those chips go into. Silicon Motion is fabless, designing its chips and outsourcing manufacturing to foundries like TSMC. Its primary customers are NAND flash makers, module makers, and OEMs. The company sells directly through its own sales force and through distributors, mostly on purchase orders rather than long-term contracts. Silicon Motion operates across three product areas: client SSD controllers for PCs (historically the largest segment at roughly 45-55% of revenue), eMMC and UFS embedded storage controllers for smartphones and IoT devices (35-45% of revenue), and enterprise SSD controllers and complete SSD solutions for data centers and AI infrastructure (a smaller but rapidly growing segment). Revenue is driven by unit volumes, ASPs, and product mix — newer-generation and enterprise controllers carry higher ASPs and margins than mainstream mobile controllers. Gross margins have historically run in the 48-50% range, with R&D as the primary operating expense. Silicon Motion's core growth thesis centers on NAND maker outsourcing: as NAND makers redirect internal R&D toward DRAM, HBM, and advanced enterprise flash, they increasingly rely on Silicon Motion to develop controllers for consumer and mobile applications. Silicon Motion is also expanding into enterprise and AI infrastructure through its MonTitan PCIe Gen5 enterprise SSD controllers and boot drives for AI data center hardware.