Constellation Energy (CEG) + Coherent Corp (COHR)

CEG’s nuclear fleet generated 182.7 TWh of electricity at a 94.7% capacity factor, and it is now selling that power into a market where prices are rising sharply. On the PJM grid — the largest U.S. power grid operator, covering 13 states and Washington, D.C. — capacity prices (payments utilities receive just for having power plants ready to generate) rose 445% year-over-year, and day-ahead energy prices rose 49%. CEG has signed 20-year Power Purchase Agreements (PPAs) with Microsoft and Meta — long-term contracts in which those companies agree to buy electricity at a set price for years — converting the fleet from an old-style commodity producer into contracted clean-energy infrastructure. The restart of the Crane nuclear plant ($1.6B for 835 MW) is an all-or-nothing risk: it either succeeds or fails, with no middle ground, and hinges on approval from the Nuclear Regulatory Commission (NRC) and connection to the PJM grid.

COHR’s Networking segment ($3.4B in revenue, +49% year-over-year) is supply-constrained, not demand-constrained — meaning the problem is not finding buyers, but making enough product to fill the orders already in hand. In Q2 FY2026, the book-to-bill ratio for data center transceivers (devices that send and receive data over fiber-optic cables at extreme speeds) exceeded 4×, meaning orders were coming in 4 times faster than COHR could ship products. The key bottleneck-release is the transition to 6-inch wafers of Indium Phosphide (InP), a semiconductor material used to make lasers for fiber-optic communication. This shift yields more than 4× the chips per wafer at less than 50% of the cost per chip. Calendar year 2026 production is largely booked. Management does not expect supply to catch up with demand in CY2026 or CY2027.

The three themes converge at the data center buildout. CEG’s data center customers increased their energy usage 45% over two years. COHR’s data center revenue grew 36% year-over-year. Nuclear PPAs (CEG) provide the power; optical transceivers and silicon photonics — technology that uses light instead of electricity to move data inside and between chips — (COHR) provide the interconnect bandwidth. PJM’s forecast calls for 30 GW of new data center power demand through 2030 — and even if that figure is overstated by 3–5×, as some industry participants suggest, it still implies sustained demand for both clean baseload generation and high-speed optical networking.