Three chip suppliers sit between artificial-intelligence processors, moving data across a rack rather than doing arithmetic inside it. All three reported June quarters within a fortnight, and the results point in different directions. The share prices have not.

The one that is accelerating and de-rating

Coherent, a laser and photonics manufacturer that makes the indium-phosphide chips and optical transceivers inside data-center networks, posted record revenue of $2.05bn in the June quarter, up 33.7% year on year. Its Datacenter & Communications segment was 79% of that, and data-center revenue rose 66% year on year and 24% sequentially on 800-gigabit and 1.6-terabit transceiver demand — a third consecutive quarter of double-digit sequential growth. Gross margin has now expanded four quarters running, to 38.5%. The company produced roughly 80% more indium-phosphide lasers than a year earlier and expects to double internal capacity a quarter ahead of plan, moving to six-inch wafers that yield four times the output at half the cost.

The shares fell 24.8% over the same three months. Coherent trades at 20.8x trailing gross profit, down from about 30x in late May and below the 25x it carried in early May. Its trailing price-to-earnings ratio of 65.3 compares with 30.1x forward. In early May that trailing multiple was above 300 — the earnings arrived; the price did not follow.

The one priced for it

Astera Labs sells retimers, switches and modules that keep signals intact across the PCI Express and CXL fabrics linking accelerators to each other and to memory. Revenue reached $392.4m, up 104% year on year and 27% sequentially, at a 73.3% gross margin. Management guided the September quarter to $540m-$560m, roughly 40% sequential growth, with operating margin near 43%. Its Scorpio X switches entered volume production a quarter early and should be the largest product family by revenue this quarter, with more than ten customers engaged and content above $1,000 per accelerator.

That is the cleanest acceleration of the three, and it is fully in the price: 54.3x trailing gross profit, dearer than either peer and no cheaper than the 52.3x it carried in early May despite falling 21% from its August high.

The weak leg

Credo Technology makes active electrical cables and the signal-conditioning silicon inside them — copper links up to about seven metres that draw roughly half the power of optics, a market it holds some 80-88% of, ahead of Marvell and Broadcom. Fiscal 2026 revenue tripled to $1.335bn at a 68% gross margin, and operating margin reached 35.7%.

The headline growth rate is backward-looking. Sequential growth ran 51.9% in the January quarter, then 7.4% in the May quarter, and guidance implies about 7.6% again. Consensus has fiscal 2027 revenue at $2.46bn, which requires the remaining three quarters to average roughly 12-15% sequential growth — a re-acceleration the current guide does not contain. Concentration is extreme: the top three customers were 34%, 27% and 16% of the latest quarter. Credo's multiple, at 47.3x trailing gross profit, is essentially where it stood in early May, even as the growth path changed underneath it. Results land after the close on 1 September.

Why they fell together

Nothing in August came from these companies' order books. Early gains followed a report that the Federal Communications Commission (FCC) was drafting a ban on new Chinese optical transceiver imports. The reversal came on 18 August, when the 30-year Treasury yield hit a 19-year high of 5.33% and chip stocks sold off across the board. That transmission is newer than it looks: hyperscalers' incremental annual borrowing rose from 9% of capital spending in fiscal 2024 to 32% of the trailing twelve months by mid-2026, so long-bond yields now price their suppliers directly. A day earlier, contract optics assembler Fabrinet reported record revenue up 45% at a gross margin of 11.99% and fell 20%, dragging the complex with it.

Volatility here is not new. Since mid-June, Credo has moved 5% or more on 22 of 43 sessions, Coherent on 23, Astera Labs on 21 — against one such session for Nvidia. The unresolved question underneath is physics: copper links stop working past roughly two metres, and in March a group including Nvidia, Broadcom and Meta founded a consortium to define a common optical layer for rack-scale connections. Credo has bought its way toward optics through DustPhotonics; Astera Labs through aiXscale. Coherent already sells the lasers.

The setup

Where it stands — Coherent's business is accelerating into a falling multiple; Astera Labs' is accelerating into an unchanged one; Credo's is decelerating into an unchanged one. Would confirm — Credo guiding its October quarter below 12% sequential growth on 1 September. Would invalidate — Coherent's December-quarter data-center revenue growing under 10% sequentially, or gross margin slipping below 38.5%. Watch next — Credo's fiscal first-quarter results, after the close on 1 September, against guidance of $465m-$475m. Valuation — Coherent 20.8x trailing gross profit and 14.0x forward, versus 25x in early May; Credo 47.3x, Astera Labs 54.3x.