Soitec's Q1 shows its photonics wafer monopoly turning into growth. It makes the Photonics-SOI substrate under nearly every silicon photonics chip, from TSMC's COUPE to Applied Optoelectronics and Coherent transceivers and Nvidia and Broadcom CPO switches, with 95%+ share. Photonics-SOI sales doubled to over half the €65M Edge & Cloud AI segment. Revenue of €113M rose 23% at constant currency versus 15% guided, Q2 guidance is 30%+ versus 4% expected, and its Singapore 300mm fab qualified early. … Show more

Soitec holds a monopoly on the Photonics SOI wafers the AI photonics trade runs through, yet trades at just 3.6x forward EV/revenue. Silicon photonics chips in AI data centers, from transceivers to Nvidia switches and Broadcom ASICs, are built on it via its proprietary Smart Cut process; GlobalWafers exits by 2027 and Shin-Etsu sells little. Optical interconnect grows from about $10 billion to over $70 billion by 2030, and top customer Tower Semiconductor targets 5x capacity by end-2026. x.com 

Soitec now looks overextended after a rapid run, and a pullback is likely. The AI photonics bottlenecks behind the thesis are real, but it is hard to judge what premium each name deserves, which makes the stock hard to value at these levels. x.com 

Soitec's chokepoint thesis is being validated as silicon photonics goes mainstream. UBS estimates it holds 95% of the substrate market for silicon photonics chips, and revenue usually flows through such a monopoly-like position. Soitec now expects 80% of more than 10 capacity reservation agreements within one to two weeks and calls $200M of photonics-SOI revenue absolutely a floor. TSMC sees silicon photonics topping 50% of the optical transceiver market in 2027. x.com  x.com 

Soitec's photonics-SOI business is accelerating sharply, making the stock cheaper on a bull case that still needs to play out. Q1 FY27 revenue rose 23% organically to €113m, with photonics-SOI up about 100%; Q2 is guided up over 30% and FY27 photonics revenue should more than double. If photonics becomes supply-constrained, near-idealistic 40-42% EBITDA margins on €750m revenue imply about 11x FY28 EV/EBITDA, versus 13.3x on prior consensus. Below about 70, confidence would return. x.com 

Soitec gains from co-packaged optics, which multiply its Photonics-SOI content about 4x per optical port, from roughly 50mm² in a pluggable to 200mm² in a CPO switch. Its proprietary Smart Cut process, with over 4,300 patents and 12-24-month foundry qualification lock-in, gives it over 95% of photonics substrates. Morgan Stanley upgraded it to overweight with a €70 target, up from €35, citing an underappreciated mix shift that should expand gross margins. x.com  x.com  x.com 

Soitec's guidance shows AI optical demand turning into real revenue upstream, in the silicon-photonics substrate layer. It now expects $250M-$300M of Photonics-SOI revenue in FY2027, up from just over $100M, driven by AI data-center optical connectivity. Q2 Photonics-SOI revenue should triple and overall Q2 growth guidance rose to about 50% from over 30%. Planned multiyear deals with eight of about ten major customers suggest they see it as strategic supply. This isn't purely a CPO signal. x.com 

Soitec holds a near-monopoly on photonics-grade SOI wafers, the irreplaceable base for mass-produced silicon photonics in AI data centers, giving it 5x potential. SOI's oxide layer keeps light in the top silicon waveguide, and Soitec is the only supplier certified by TSMC, GlobalFoundries and Tower, with over 80% share. Revenue fell 22% year over year on customer destocking, and a CEO exit and withdrawn guidance are noise; 1.6T and CPO should drive the ramp over 2-3 years. x.com  x.com 

Soitec's SOI wafers remain necessary no matter who builds optical engines if co-packaged optics standards take hold. Around 95% of these photonics wafers come from Soitec, so consolidation among module makers changes the buyer, not the need for wafers. Large buyers such as TSMC or Broadcom could pressure pricing and seek a second source, though none is apparent before 2030. That pricing risk is by far smaller than the module makers' architecture risk. x.com 

Soitec wins from Google's TPUv8i regardless of which foundry builds the chips, because it supplies the photonics-SOI wafers upstream. TPUv8i's silicon-photonics optical circuit switch adds a new layer of large photonic dies, and its signal loss forces transceivers to go coherent, using about 2-2.5x more silicon per port and roughly 3-4x the wafer starts. Risks include coherent modulators moving to indium phosphide or thin-film lithium niobate, and Marvell building its own photonics. x.com