Tokyo Ohka Kogyo — AI supply-chain exposure

Tokyo Ohka Kogyo is a photoresist pure-play — it makes little besides the light-sensitive coatings and related process chemicals that fabs use to define circuit patterns on wafers. It sits in the materials layer as a supplier to foundries, and it carries the largest global share of the resist market, extending into the EUV resists that leading-edge nodes require to pattern their smallest features.

The structural hook is that resist is a modest line item on a chip's bill of materials but an absolute prerequisite, and the club that can qualify EUV-grade formulations is tiny. That concentration gives Tokyo Ohka Kogyo durable pricing power and makes it hard to design out once a process has been locked in around its chemistry. The model weights it mid-chain: not central in the way logic is, but a consumable bottleneck that the whole leading edge quietly leans on.