Monolithic Power Systems, which designs the direct-current voltage regulators that turn rack current into the specific volts an artificial-intelligence accelerator runs on, has agreed to put its proprietary process technology inside somebody else's fab. The long-term manufacturing agreement with GlobalFoundries, announced September 9, opens capacity at a 300mm Singapore plant for automotive, industrial-robotics and AI power stages from early 2027. Eight days earlier the same foundry delivered Navitas Semiconductor's first American-made Gen 5 gallium-nitride parts from its Vermont plant.

Neither company's story advertises the overlap, and it matters because the two sit at opposite ends of the same few inches of copper under a server board: Monolithic Power converts the last step down to the processor and already gets paid for it; Navitas, a 190-employee Torrance designer of gallium-nitride and silicon-carbide power devices, is priced on an architecture that has not shipped. Both now need one supplier's 2027 capacity. Three dated things have happened since: a research note, a rate decision, and a reversal in both share prices.

The half that is accelerating

Monolithic Power's June-quarter revenue was $980.6m, up 47.6% year on year and the fourth consecutive quarter of faster growth. Enterprise data — the accelerator and server business — reached $380.6m, up 164.3%, taking that segment from roughly a fifth of company revenue to 38.8% in a year, and the company lifted its full-year growth floor for the segment from 85% to 130%. Gross margin was 55.2%, inside the same narrow band it has held for eight quarters, so the mix shift has cost nothing at the gross line. Operating margin widened to 31.0% from 24.8%. Third-quarter revenue is guided to $1,140m–$1,160m, a midpoint 56% above the year-ago quarter.

Management said on the July 30 call that channel inventory was "very low," that book-to-bill sat well above 1.0, and that enterprise data has "no concentrated customers." Founder-chief executive Michael Hsing told investors on that call that the company "relies on its own silicon carbide devices for the 800-volt solution" — an internal answer to the architecture change, sampling rather than shipping.

Against that, the valuation has come down hard. Priced against trailing gross profit, Monolithic Power has fallen from 49.8x in early May to 33.1x, 26.1x on forward estimates, while gross profit itself grew 47.8%. Market capitalization is $59.8bn, against $81.2bn in May. The de-rating is not estimates falling: consensus has revenue up 49.2% this year and earnings per share up 54.8%.

The complex fell in order of price, not of sockets

On September 14 the stock lost 7.4% in one session on a research note questioning its allocation on Nvidia's next accelerator platform — the same category of event that took it down 24.7% in five sessions in November 2024, when Renesas and Infineon were reported to have taken Blackwell regulator work. The threat is real and named: Analog Devices paid $1.5bn for Empower Semiconductor, whose vertical regulators sit in exactly that position, and Nvidia's own 800-volt supplier list runs to ten silicon vendors, Monolithic Power and Navitas among them. A place on a list is not a socket.

But the three-month cross-section does not read like a socket being reassigned. Every power and analog name fell: Navitas 52.4%, Vishay 49.9%, onsemi 42.5%, Power Integrations 42.2%, STMicroelectronics 36.0%, Monolithic Power 22.1%, Texas Instruments 17.4%, Analog Devices 13.5% — while an S&P 500 fund rose 2.0% and Nvidia itself rose 5.5%. Monolithic Power was the fourth-mildest faller of twelve. The ordering tracks starting valuation and how far out the cash flows sit. The Federal Reserve raised its benchmark rate a quarter point to 3.75%–4% on September 16, its first increase since 2023, with the ten-year Treasury yield above 5% for the first time since 2007 — which is a direct tax on 2027 revenue. Both stocks bottomed within a session of the decision and turned up; Monolithic Power rose 6.6% off its September 15 low on the heaviest volume in a fortnight.

Navitas: the date moved, the revenue did not

Navitas booked $10.5m of revenue in the June quarter, down 27.3%, at a gross margin of minus 9.5%. Across four quarters it produced cumulative gross profit of minus $0.6m on $36.5m of sales — a year of shipping product at no gross profit. September revenue is guided to $13.5m, which would be the first year-on-year growth in five quarters. Solvency is not the issue: $557.4m of cash and no debt against roughly $68m of annual cash burn. Dilution is — shares outstanding rose 18.5%, including $373m raised at $21.89, nearly double the current price.

The date is the harder problem. On the July 27 call management put gallium-nitride content inside accelerator voltage conversion at mid-to-late 2027; six weeks later, at Citi's Global TMT conference on September 8, chief executive Chris Allexandre dated native 800-volt systems to early 2028. "It would have happened without NVIDIA, it's happening much sooner due to their influence," he said of the shift. Consensus has revenue of $47.7m this year, up 4.7%, and no positive earnings before 2030, against 62.6x forward sales.

What each side earns

Monolithic Power's fall is mostly duration and an extreme starting point, not a broken business: its numerator shrank while its denominator grew 47.8%, and the three disclosures that would have to crack — inventory, book-to-bill, concentration — have not. What the business does not yet explain is why it should still be the most expensive name in the group, at 26.1x forward gross profit against roughly 17.7x for Analog Devices, when the buyer of its main socket has just bought a competitor. Navitas's de-rating is earned outright: a company selling below cost, with its defining revenue pushed two quarters further out in six weeks, was never going to hold 80x sales through a rate increase.

Neither company has published a third-quarter reporting date; Monolithic Power's own precedent is the last week of October. Until one of them prints, the only new hard fact either has given investors this month is where the wafers will come from.