The company behind the “xPhone partner”

Filtronic PLC (FLTCF) is the company at the center of Alexander Green’s Oxford Club promo, “Elon’s Secret xPhone Partner: The Tiny Supplier SpaceX Can’t Replace.” Filtronic is a radio-frequency engineering firm based in the United Kingdom, and it trades on London’s AIM market under the symbol FTC and on the US OTC market as FLTCF. The teaser describes it as “roughly 2,000 times smaller than SpaceX,” trading “around $3 a share,” with nearly 50 years spent “obsessing with one single problem: how to push a radio signal harder, cleaner, and farther than anyone else.”

That description is more accurate than most promo copy. Filtronic really is a specialist in radio-frequency hardware, and it really has spent decades in exactly that niche. The product that matters for this story is the solid state power amplifier, or SSPA, a device that boosts a radio signal so it can travel the long distance between a satellite and a ground station.

What Filtronic actually sells

Filtronic builds its amplifiers on gallium nitride, a semiconductor material that handles high frequencies and high power efficiently. These are the E-Band amplifiers used for satellite backhaul, the data links that carry traffic for constellations like Starlink. When a satellite relays data down to a ground station, or when ground stations beam instructions back up, an amplifier like Filtronic’s is doing the heavy lifting.

That is the distinction the promo slides past, and it matters. Filtronic’s amplifiers support the plumbing that keeps a constellation’s data moving. They are not the direct satellite-to-phone chips that a hypothetical xPhone handset would need. We break down that difference in our direct-to-device satellite explainer.

The SpaceX relationship is real

The core fact in the pitch checks out. In April 2024, Filtronic entered a strategic partnership with SpaceX, and the first order was described as worth roughly as much as Filtronic’s entire prior year of revenue. SpaceX took equity warrants, initially up to a 10 percent stake, expanded to 15 percent in March 2025, with vesting tied to deliveries rather than orders. That is a real, verifiable relationship, and it is the reason Filtronic’s stock became a momentum favorite during the spring run-up in space names.

The warrants deserve a measured read. The promo holds them up as “the strongest vote of confidence” the presenter has ever seen. In practice, warrants-for-orders is now a routine Big Tech supplier-financing practice. Amazon extracted warrants from Rivian for delivery vans, AMD offered OpenAI warrants in a compute deal, and Alphabet took Marvell warrants for its TPU program. The warrants are a cost Filtronic paid to secure and keep its most important customer, not proof the stock is mispriced.

The financials tell a quieter story

The teaser leans on “sales grew 244 percent over the past two years,” which is traceable to a real event: the one-time jump from that first large SpaceX order. The run-rate since has been flat. Filtronic’s last four semi-annual revenue figures were about £25.6 million, £30.7 million, £25.3 million, and £30.3 million, and the most recent full fiscal year saw revenue fall about one percent. That is stasis, not momentum, and it sits awkwardly next to a “10X in 24 months” claim. The US OTC quote closed at $3.58 on September 9, 2026, with thin volume on the pink sheets.

The concentration risk is the part the promo never mentions. SpaceX was about 60 percent of Filtronic’s revenue last year, down from over 80 percent the year before. That is improving, but it is still a company whose fate is tied to a single customer with a documented habit of bringing suppliers in-house. For more on how that plays into the return math, see our Filtronic stock analysis.

The competition and the integration risk

Filtronic is not the only company that can build these amplifiers. The competitor set includes MACOM, Teledyne, Qorvo, and Stellant Systems, all of which have radio-frequency and defense heritage. The promo frames Filtronic as irreplaceable, but the honest version is that it is one of a short list of qualified suppliers, which is a good position but not a monopoly. The larger risk is vertical integration. Tesla and SpaceX have a long record of bringing suppliers in-house when a component becomes strategically important, and SpaceX has already shown it will build its own silicon when it wants to. If the amplifiers Filtronic supplies ever become a bottleneck rather than a commodity, the customer has both the capital and the engineering talent to do it themselves. That is the scenario the “can’t replace” framing quietly assumes away.

The bottom line

Filtronic is a legitimate, interesting company and a real SpaceX supplier with a defensible niche in a growing market. The right questions are whether its GaN amplifier business keeps scaling as the Starlink constellation grows and whether it can diversify beyond one dominant customer, not whether the stock goes up 10X. Watch the company’s fundamentals, not the xPhone story.

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