DCI growth hides datacom and customer risk
- Fabrinet is a contract manufacturer for hard-to-build optical, electro-mechanical, and electronic products.
- Q3 fiscal 2026 growth was led by Telecom and DCI, not by old-style Datacom.
- DCI revenue rose 121% from last year in Q3 fiscal 2026, making it the clearest AI networking driver.
- Traditional Datacom fell 21% from last year, and the new HPC line fell 56%.
- The top three customers were 51.5% of Q3 fiscal 2026 revenue, so one program cut can matter a lot.
AI buildout, with sharper edges
Fabrinet looks like a quiet winner in the AI network buildout. It does not sell chips. It builds difficult optical and electronic products for the companies that sell networking gear and computing systems. The newest filing makes the story clearer: DCI, short for datacenter interconnect, is now broken out and grew 121% from last year in Q3 fiscal 2026.
That matters because the old story treated AI exposure as mostly a Datacom story. The new segment view says something different. Telecom and DCI are carrying growth, while traditional Datacom fell 21% from last year in the same quarter. That split makes the business look stronger in one place and weaker in another.
The bull case is that DCI keeps growing as big cloud and AI customers connect more data centers. Automotive also helps, with revenue up 28% from last year in Q3 fiscal 2026. Management is adding capacity through Building 10, a 2 million square foot facility, which points to confidence in future demand.
The bear case is concentration and timing. NVIDIA and Cisco were 27.6% and 18.2% of fiscal 2025 revenue, and the top three customers were 51.5% of Q3 fiscal 2026 revenue. HPC also shows how fast a new line can fade, falling 56% from last year after a quick ramp. Finn's score is solid, not loud, because growth is real but the price and customer risk still need respect.
Factory partner for complex gear
Fabrinet makes money by building advanced products for original equipment manufacturers, often called OEMs. These customers design the gear. Fabrinet handles complex manufacturing, optical packaging, precision assembly, and testing at scale.
The model works best when a customer has a hard product that must ramp quickly. Fabrinet becomes deeply tied into that product program, which can make it hard to replace. The upside is strong volume when the program wins.
The weak point is the same feature. A few large customers drive a large share of sales. If a key customer delays a product, switches suppliers, or sees weaker end demand, Fabrinet can feel the hit quickly.
Capacity is another bet. Building 10 adds a large amount of manufacturing space before all future demand is locked in. If DCI and next-generation products keep scaling, that space can help. If program ramps slip, the added capacity could weigh on returns.
Where the growth is shifting
Telecom
Telecom was $455.0 million in Q3 fiscal 2026 revenue and grew 12% from last year. It has moved from an inventory-digestion problem into a main support for growth.
Datacom
Datacom was $199.1 million in Q3 fiscal 2026 revenue and fell 21% from last year. The watch item is whether the 1.6T transceiver ramp brings this line back to growth.
Datacenter Interconnect
DCI was $183.4 million in Q3 fiscal 2026 revenue and grew 121% from last year. These modules connect data centers, which makes DCI the clearest AI networking growth line.
Automotive
Automotive was $166.4 million in Q3 fiscal 2026 revenue and grew 28% from last year. It gives Fabrinet a second growth path outside optical networking.
Industrial Lasers
Industrial Lasers was $39.5 million in Q3 fiscal 2026 revenue and fell 2% from last year. This is not the main story today, but it adds some mix outside telecom and datacom.
High-Performance Computing
HPC was $12.3 million in Q3 fiscal 2026 revenue and fell 56% from last year. It could become useful again, but the drop shows that new programs can be uneven.
Others
Other non-optical revenue was $58.1 million in Q3 fiscal 2026. This bucket is smaller and less clear, so it matters less to the current thesis than DCI, Telecom, and Automotive.
Q3 fiscal 2026 revenue mix
The mix below uses Q3 fiscal 2026 revenue by product line. Customer concentration is high: the top three customers were 51.5% of total revenue in that quarter.
What could break the thesis
Top customer cutback
High impact · Medium oddsFabrinet depends on a small group of large customers. NVIDIA and Cisco were 27.6% and 18.2% of fiscal 2025 revenue, and the top three customers were 51.5% of Q3 fiscal 2026 revenue. A lost program or slower order plan from one major customer could move total revenue.
DCI growth slows
High impact · Medium oddsDCI is now the clearest growth engine after rising 121% from last year in Q3 fiscal 2026. If that growth slows sharply, the AI networking story becomes less powerful. Telecom could still help, but investors may pay less for the stock if DCI stops carrying the story.
Datacom ramp misses timing
Medium impact · Medium oddsTraditional Datacom fell 21% from last year in Q3 fiscal 2026. Management had linked improvement to next-generation 1.6T products. If that ramp is late or smaller than hoped, one of Fabrinet's older growth lines may stay weak.
HPC stays volatile
Medium impact · Medium oddsHPC is a new disclosed line, but it fell 56% from last year in Q3 fiscal 2026. That drop shows that non-optical growth can be tied to narrow programs. If HPC does not stabilize, the non-optical story rests more on Automotive alone.
Tariffs and tax changes raise costs
Medium impact · Medium oddsFabrinet flagged U.S. global trade tariffs imposed in April 2025 as a risk. Tariffs can raise costs, disrupt supply chains, or reduce demand for customer products. The One Big Beautiful Bill Act also adds tax uncertainty, even though the company said the initial impact was not material.
In one breath
Is Fabrinet an AI stock?
Fabrinet has AI exposure, but it is not a chip designer. Its clearest AI-linked line is DCI, which helps connect data centers and grew 121% from last year in Q3 fiscal 2026.
Why did the Fabrinet story change?
The company now reports more detail inside Optical and Non-Optical Communications. That showed DCI and Telecom driving growth, while traditional Datacom and HPC were weak.
Who are Fabrinet's biggest customers?
For fiscal 2025, NVIDIA was 27.6% of revenue and Cisco was 18.2%. In Q3 fiscal 2026, the top three customers were 51.5% of total revenue.
What is the main thing to watch next?
Watch whether DCI keeps growing fast and whether Datacom turns up with the 1.6T ramp. Also watch HPC, because its sharp drop raises questions about how steady that new line can be.