GlobalFoundries runs its photonics fabs full while Tower banks $290 million in deposits
DIGITIMES puts GlobalFoundries' Singapore fabs above 90% utilization with tool waits of up to two years, while the AI-optics cycle's capacity deposits land at Tower, STMicroelectronics and Soitec. GF reports third-quarter results on 4 November with the stock at $48.68 against a $60 Stifel target.
Vincent Jiang · 3 min read
Singapore is full, and the tools are two years out
Singapore is where GlobalFoundries prints the photonic chips behind AI data-center links, and the constraint is equipment lead time, not demand. Utilization at GF's Singapore fabs has moved above 90%, DIGITIMES reported on 30 September, and Singapore manufacturing chief Yew Kong Tan put tool waits at as long as two years, the cap on how fast the photonics business can grow 12. GF has not disclosed the utilization figure itself 1.
That gap between full and growing is what the market has to price. GFS closed at $48.68 on 1 October, 47% below the $92.55 top of its 52-week range and well clear of the $32.02 low, a $26.7 billion market cap against a $60 Stifel Buy target, with third-quarter results due 4 November 3.
Customers are paying ahead, just not in GF's disclosures
In this cycle, optical customers pay before the capacity exists, and none of that money shows up in GF's disclosures 4. Tower collected $290 million of silicon-photonics prepayments in the first quarter, mostly to reserve 2027 capacity, and holds about $1.3 billion of contracted 2027 photonics revenue 5.
STMicroelectronics is signing long-term agreements with cash advances, and Soitec, which holds roughly 95% of the 300mm Photonics-SOI wafer beneath every fab in this layer, is lining up multi-year reservations with eight of its roughly ten major customers 4. GF discloses no comparable deposits 4. A full fab is not a prepaid fab.
Tower's photonics run-rate already passes GlobalFoundries' 2026 guide
- 2026 silicon photonics revenue
- Estimate
Data
| 2026 silicon photonics revenue | |
|---|---|
| Tower (Q2 run-rate) | $680M |
| STMicroelectronics (sell-side model) (estimate) | $800M |
| GlobalFoundries (>$400M guide floor) (estimate) | $400M |
The map has already moved
GF guided 2026 photonics revenue to more than double a base above $200 million 4. Tower's reported second-quarter run-rate of $680 million already sits past it, and the 1 October map of the foundry layer reads Tower as having taken the revenue lead, past GF's "largest pure-play" claim from its Advanced Micro Foundry purchase 54.
The bonding step co-packaged optics needs next runs inside TSMC's captive SoIC line, a service GF does not sell 4. The wider business grew revenue 5.8% year over year in the second quarter, to $1.79 billion 36.
Eight quarters of GFS revenue, still inside a $1.6 to $1.8 billion band
Data
| Revenue | |
|---|---|
| Q3 '24 | $1.74B |
| Q4 '24 | $1.83B |
| Q1 '25 | $1.59B |
| Q2 '25 | $1.69B |
| Q3 '25 | $1.69B |
| Q4 '25 | $1.83B |
| Q1 '26 | $1.63B |
| Q2 '26 | $1.79B |
Deals instead of deposits
GF's counter is agreements. The expanded Marvell silicon-germanium deal struck 17 September moved the shares about 4% 7, the SMART Photonics indium-phosphide service followed on 21 September 8, a Monolithic Power process partnership ramps in Singapore early 2027 1, and a $300 million Commerce Department letter of intent extends the Washington money The Inference tracked on 29 September 4.
The mechanism is the risk. Agreements commit demand, but they carry no disclosed cash, so the expansion runs on GF's own balance sheet while the tools are two years out 24. Commitments, all of them, and none with a deposit disclosed 4.
What 4 November has to show
The pricing power is visible one layer up: TSMC is raising wafer prices 3% to 6% from January 2027, on order books supply-chain sources say run to 2030 9.
If Singapore's tightness converts into GF pricing, the Q3 print shows it, against an earnings-per-share guide of $0.46 to $0.56 3. If the deposit ledger keeps filling at Tower, STMicro and Soitec, GF holders own a claim on the queue, not the queue itself.
Deepdive
AI-generated from this story and its cited sources. Not investment advice.
