Filtronic‘s (LSE:FTC) already gone to the moon over the past five years by blasting above all others in the FTSE AIM All-Share Index. We’re looking at a mind-blowing return of around 3,180%.

To put that number into perspective, a £5,000 investment made in early May 2001 would now be worth roughly £164,000!

Yet I think this stock could head even higher in the coming years. Here’s why.

Game-changing partnership

For those wondering what Filtronic does, it’s a maker of advanced radio frequency (RF) solutions for the aerospace and defence, space, and telecoms infrastructure markets. So that’s various filters, transceivers, amplifier systems, and so on.

The firm is a leader in E-band solid state power amplifiers (SSPAs). As it points out: “Companies like SpaceX have received the approval to use E-band (71-86GHz) frequencies for its Starlink-network, and it’s a sign of where the satellite industry is heading… E-band delivers high-capacity, low-latency connectivity ideal for next-generation satellite networks“.

Filtronic already supplied SpaceX with SSPAs for the ground segment of its Starlink network, which provides high-speed internet via low-earth orbit satellites. But a strategic partnership signed between them in early 2024 immediately sent the stock up 50%.

The game-changing agreement included:

• An initial order of $19.7m (£15.8m) for SSPA modules.
• A commitment to ongoing orders for the next five years.
• SpaceX was issued warrants for up to 10% of Filtronic’s share capital.
• A collaboration to focus on additional frequency bands.

The equity stake gives SpaceX a vested interest in Filtronic’s financial success. As evidenced in August 2025, when a record $62.5m contract for Filtronic’s next-generation GaN E-band product sent the share price surging again.

SpaceX IPO

SpaceX is gearing up for a potentially record-breaking $1.75trn stock market debut this summer. It could net the rocket and satellite giant up to $75bn in cash.

Now, we already know SpaceX will use a decent chunk of this to scale up Starship, its gigantic reusable rocket and spacecraft launch system. It’s designed to deploy massive batches of next-generation Starlink satellites (potentially hundreds at once).

Presumably, if SpaceX uses IPO funds to massively increase the Starlink constellation, and also develop space-based AI data centres, that will require more ground-based infrastructure. And that’s surely fantastic news for Filtronic’s order pipeline. The firm has already moved into a larger headquarters and manufacturing facility to support the anticipated expansion.

Lumpiness

That said, growth’s unlikely to be linear. Revenue for this fiscal year (FY26), ending May, is expected to be broadly the same as FY25, at about £55m. Therefore, earnings can be lumpy, inviting share price volatility.

On top of this, the valuation’s now very high (albeit far cheaper than the mooted SpaceX valuation). Based on the £75m revenue forecast for the 2027/28 year (FY28), the forward price-to-sales ratio is around 8.5.

If sales growth fails to materialise, the stock could end up badly overvalued.

Worth a look?

Looking ahead though, it’s hard not to be bullish on Filtronic’s future growth trajectory, especially when adding in emerging opportunities across the European SpaceTech and defence sectors.

Its new high-powered V-band amplifiers open up further opportunities in medium earth orbit and geostationary for the first time.

Weighing things up, I think the Starlink and defence growth potential make the stock worth considering for the next five years.