AI bandwidth demand still favors Coherent and Lumentum, but tight customer financing can delay orders and lasting valuations need durable profits. A model provider losing share need not reduce total bandwidth use. Coherent could beat and raise guidance; Lumentum may only meet estimates this quarter, improving next quarter. If margins partly reflect scarce indium phosphide, added supply will test whether upgrades, volume and cost gains sustain earnings. These earnings calls remain forecasts. … Show more

Marvell risks paying a peak-scarcity price for Lumentum if optical supply catches up by 2028-30. The proposed ~$99B deal values Lumentum at roughly 20x guided annualized revenue and 58x estimated after-tax operating income, while Lumentum, Coherent and Chinese suppliers are adding laser capacity. The DSP-and-laser combination has strategic logic, but durable scarcity economics and Nvidia's response remain uncertain. 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 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 

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's permit-backed Q4 outlook weakens the near-term operating objection to the Sell case. Q3 revenue reached $73.4M at 56% GAAP gross margin; management guides to about $90M in Q4 from business permitted or not needing permits. InP contributed $54.3M and backlog exceeds $500M, though much spans years. The remaining test is whether 2027 capacity becomes qualified, permitted shipments at durable margins. x.com  x.com  x.com 

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 

AXT stays central to the InP substrate thesis because Coherent's 6-inch ramp relieves only its own device capacity and pushes the constraint upstream to substrates. Coherent does not plan to sell InP lasers externally soon, so the merchant shortage persists, which is also the context for Lumentum's long-term agreement with AXT. AXT's InP is made in Beijing, and China's InP export licensing remains despite the topic being raised in the Trump-Xi talks, so permission is the key variable. x.com  … Show more

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

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