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 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 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 

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

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 

Lumentum and Coherent are investments driven by product iteration, while AXT is a bottleneck trade best treated as speculation. Shortage-driven price hikes on the same parts define a cyclical stock, prices quickly discount shortage expectations, and once profits truly climb it is time to exit. Bottlenecks also push customers to design around them and invite new entrants. Investable companies keep lifting margins through yield gains and new products, driving token deflation while growing revenue. … Show more

InP substrate demand and pricing still support the AI optics supply chain. Yunnan Germanium reports higher InP volumes from AI data centers and optical communications, plus higher prices. Q3 revenue rose 134.6% year on year, near AXT's guided 136%, but also includes germanium. IQE's H1 photonics grew 45%, partly from US defense funding. AXT's $66m Q3 guide covers only licensed exports or sales needing no license; a miss would more likely reflect licensing. x.com 

Optics and photonics should be among AI's biggest winners as faster GPU networks need optical connections that suppliers cannot expand quickly enough. Lumentum says some components are sold out through early 2029; Sivers is investing $30M to target more than 100M lasers a year, with operations expected in Q4 2027. Potential US restrictions on Chinese transceivers could reshape supply in 2027. Applied Optoelectronics and Sivers are the favorites. x.com  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's Q2 2026 results confirm its role as an upstream indium phosphide supplier to AI optical modules. Revenue rose 164% year on year to $47.6 million, well above $30.4-34.1 million consensus, with GAAP net income of $11.1 million and adjusted EPS of $0.19 versus $0.07 expected. Lumentum signed an InP substrate capacity reservation through 2031 with $87 million of prepayments. InP revenue hit a record and backlog topped $100 million as data-center links move to 800G and 1.6T. x.com