On 29 September Everspin, the only listed pure-play maker of magnetoresistive RAM, demonstrated what it called the world's first memory platform connected over Compute Express Link, the standard for hanging extra memory off a processor via the PCI Express bus. The memory modules were its own one-gigabyte PERSYST parts. The controller was not: the demonstration ran Wolley controller logic on an AMD Alveo programmable chip inside a Supermicro server, with an AMD EPYC processor, and Everspin claimed write speeds up to 100 times faster than NAND solid-state drives for saving AI training checkpoints.

That is the first physical referent for a category label three companies have been filed under while none of them sells the part that defines it. Rambus told investors on its 27 July call that Compute Express Link is a "fragmented ASIC market" and that its role is enablement and licensing intellectual property for other companies' chips. Everspin borrowed a controller. Microchip sells switches for the older bus. The group nonetheless rose together through September, Rambus by 32.2% in the month to 2 October, and the question is which businesses paid for that.

A record quarter built on a defense contract, not on servers

Everspin's June quarter was a record $18.7m, up 41.9% year over year after three straight quarters of acceleration. Product revenue of $15.3m, up 38%, came from industrial automation, European energy management and aerospace and defense sockets. The other $3.4m was first partial recognition on a $40m, 30-month Toggle MRAM subcontract with prime contractor Amentum under a US government microelectronics program, a contract worth roughly 72% of trailing annual revenue. Results were "driven by strong product revenue coupled with initial non-product revenue under our recently signed $40 million contract with a US prime contractor," chief executive Sanjeev Aggarwal said on the 5 August call; management warned recognition follows a bell curve.

What holds that position is qualification, not cost. Aggarwal called Everspin the "singular domestic provider of MRAM to the U.S. government" at the Lytham Partners summit on 18 August. The bill for defending it is visible: operating expenses reached $14.5m from $8.7m, including $4.0m of patent litigation brought by Avalanche Technology, and the operating loss widened to $4.4m. Trailing sales multiple: 7.07x on 2 October against 5.98x three weeks earlier, on a business whose operating margin moved the wrong way.

Micron's record quarter pays Rambus nothing per bit

Micron reported revenue of $54.2bn for its August quarter on 30 September with an 87% gross margin and contract DRAM prices projected to rise a further 10-15% in the fourth quarter. Rambus collects on modules, not bits. Its June quarter revenue was $207.4m, up 20.4%, with record chipset product revenue of $99.2m and royalties of $84.2m; September-quarter guidance puts product at $110-116m and royalties at $69-75m, the two largest lines pointed in opposite directions. Chief executive Luc Seraphin credited the June outperformance to processors moving from 12 to 16 memory channels — per-socket content, won generation by generation against Montage Technology and Renesas, with multiplexed-rank modules immaterial until 2027.

At 20.5x trailing price-to-gross-profit, against 16.1x on 9 September and roughly 24.4x in mid-May, Rambus is still priced at about half of Astera Labs' 39.3x forward, and Astera Labs is the one actually occupying the Compute Express Link memory-controller socket.

Microchip's shipping parts are on the older bus

Microchip's data-center revenue reached about $1bn in fiscal 2026, up 69% from $591m, with 14 PCI Express Generation 6 design wins — 12 switches and two retimers — entering production at the end of June. June-quarter revenue of $1.48bn grew 38% with gross margin of 63.2% against 53.6% and operating margin of 22.7% against 3.0%, as a brutal inventory correction unwound. At the Citi conference in early September the company said bookings were the strongest in about four years. It trades at 11.5x forward gross profit against roughly 18.7x in mid-May, cheaper than in spring on far better numbers.

So the September advance is mostly earned, and not by the category. Rambus's gross profit grew 28% and its re-rating sits below where it traded in May; Microchip's multiple fell as its margins doubled. Everspin is the one where price moved and the economics did not: revenue growth is real, but the incremental dollars are a government contract with a defined endpoint, and the Compute Express Link work earns nothing. The decisive session was 22 September, when Rambus rose 13.9% and Everspin 9.7% against Micron's 5.1% — no news at either name, memory shares rallying broadly after Goldman Sachs said the worst may be over. The likelier reading is re-coupling to a memory tape, which is also why a crossover-based decline signal still fires at Rambus: its 50-day average sits about 13% below its 200-day even with the price above both.

Everspin's demonstration will matter the day an order follows it. Until then the disaggregation parts that ship on this shelf are switches, and the standard in the label is something all three of these companies watch other people sell.