InP Substrate Supply Chain
Active BottleneckActive chokepoint — Western photonics depends on this
Active Bottleneck — Shortage Now and Through 2027+
Thesis
Indium Phosphide (InP) substrates are the foundational material for high-speed lasers (EML, DFB) used in optical transceivers and CPO. The supply chain has multiple chokepoints all controlled by a small number of players. AXT is not just an InP substrate maker — it controls raw materials (indium, gallium), pBN crucibles (BoYu JV), and holds a duopoly on final substrates with Sumitomo. IQE makes the epiwafers. If China weaponizes Vital/AXT upstream materials, Western photonics halts.
Picks in this Sector (2 active)
AXT is not just an InP substrate maker — it controls the entire upstream InP supply chain from raw materials (indium, gallium, germanium) through pBN crucible processing to final InP substrate duopoly with Sumitomo. This multi-layer chokepoint ownership means that even if competitors try to scale, they cannot without AXT's upstream materials. Retail short sellers consistently misunderstand this, treating AXT as a simple substrate company. Institutions have been silently accumulating. If China weaponizes the supply chain via Vital/AXT's JV structure, Western hyperscalers have no alternative at scale.
IQE makes InP epiwafers — the processed wafer layer between AXT's raw substrates and final laser chips. Landmark Optoelectronics (competitor) is reporting output 'far below customer needs,' validating the epiwafer bottleneck. Called at ~$100M MC, now up 260%+. MTSI invested $45M and took a board seat to secure long-term epiwafer supply — the strongest possible institutional validation of the thesis.