AXT's indium phosphide substrate chokepoint gives it pricing potential, though its Coherent agreement caps annual wafer-price increases. Channel checks suggest increases of 50-60% in Q2 2026, 10% in Q3 and over 10% in Q4. With supply agreements to Lumentum and Coherent, AXT probably becomes No. 1 ahead of Sumitomo Electric. A SanDisk-style hike now looks less likely because of the annual cap, whose percentage is redacted. x.com 

AXT cannot be the dominant indium phosphide substrate supplier when its customers' supply depends on the Chinese government's export permitting. Lumentum has locked up InP supply for several years with Sumitomo, a larger competitor that does not face the same export restrictions. Doubling down on manufacturing in China is an odd choice given continuous permitting roadblocks. Substrate pricing is unlikely to go parabolic, despite Serenity's claims of 10x+ price increases. x.com  x.com 

Sumitomo Electric is not an attractive long at about 30x earnings because too much of its revenue comes from automotive components, historically a terrible business. It is well run, with high operating cash flow and major earnings growth, and should still do well in physical AI, but there are better spots. Its equal or better InP manufacturing capability, with supply it can add fairly quickly if margins explode, instead underpins a small short on AXT. x.com 

Sumitomo Electric Industries is a growth company priced as value, at a 16.2x trailing P/E despite holding many long-term agreements with AI hyperscalers spanning fiber to lasers. AI has created a bigger medium-term anomaly, pushing value investing toward high-growth, deep-value companies. x.com 

AXT's bottleneck thesis does not hold, because AXT is not even the number-one player in its market. Sumitomo Electric can bring new capacity online within 18 months. x.com  x.com 

AXT is the upstream chokepoint of the photonics buildout, supplying the indium phosphide substrates every high-speed laser needs amid a massive global shortage. About 600,000-700,000 wafers shipped in 2025 against demand of 1.5-2 million, and AXT holds roughly 36% of a market three firms control. Record revenue rose 164% to $47.6M and gross margin hit 45% from 8.2%; Lumentum prepaid $87M to reserve capacity through 2031. The real risk is China, where slow export permits caused a guidance miss. … Show more

Applied Optoelectronics has a better chance than Coherent of delivering a 300-400 mW laser with tolerable RIN and linewidth. Its transceiver capacity ramp is also larger and is not gated by Sumitomo's 6-inch InP wafers. Long AAOI against short COHR is an unnecessarily dangerous pair trade idea. x.com 

AXT makes the substrates underneath the AI optical stack, InP, GaAs and germanium, and the market is finally noticing. InP feeds the lasers in 800G and 1.6T transceivers: no InP, no high-speed optics. Only a handful of companies produce these wafers at scale, and as hyperscalers race to upgrade AI networks, the materials layer is getting tight. Sitting at the overlooked bottom of the stack, it could be a 10x play. x.com 

AXT supplies the InP substrates that expanding optical manufacturing requires. It supplies every manufacturer, and that demand will take its shares to new all-time highs. Applied Optoelectronics is expanding capacity and selling the most cost-efficient product; a quoted post reports that Lumentum's CEO said his firm is effectively sold out through nearly 2029. x.com 

AXT sits in the optical upstream, where surging AI compute demand meets supply that cannot be built fast enough. Amazon raised 2026 capex to $220B and said even that won't meet demand, with 2027 also short. AXT posted record revenue of $47.6M, up 164% year over year, record indium phosphide revenue of $30.7M and 45% margins targeting 50%+, and is doubling capacity in both 2026 and 2027 yet still can't keep up. x.com