MACOM Technology Solutions, a 76-year-old Massachusetts maker of radio-frequency, microwave and high-speed analog chips sold into telecom networks, military radar and data-center optics, told investors on 6 August that customers had ordered 1.6 dollars of product for every dollar it shipped in the July quarter. That is a record for the company, and it came with record backlog. Revenue was $342.2m, up 35.8% from a year earlier. Operating income grew 104.8% — roughly three times the revenue growth rate. Management guided the October quarter to $415-425m and framed the next fiscal year as mid-20s percent company growth with its data-center business up about half again.

The shares are about a fifth below their 52-week high.

That gap — between order books that are still setting records and prices that peaked in the spring — runs through six other suppliers of the parts that move light and signals around an AI data center, and through two companies whose problems are entirely elsewhere.

The month is two days

Over the 30 sessions to 17 August the seven averaged a 25.3% gain, which is what makes them look like a group in motion. Remove each name's two best single sessions and the average becomes -4.5%, with five of the seven negative. Stretch the window to 90 days and the average is +0.3%; four are down. Every one of the seven lost its strongest uptrend reading between 30 June and 29 July, as the July selloff that took more than $1 trillion off global chip stocks on fears that AI infrastructure spending had peaked pulled them down together. August has been a rebound off that low, not a new trend.

What the quarters said

SiTime, a Santa Clara company with 441 employees that builds silicon timing devices — the parts that keep racks of AI servers in step — grew revenue 126.5% to $157.4m, with gross margin at 63.0% against 51.9% a year earlier. Its communications and data-center unit reached $101m, a ninth straight quarter of triple-digit growth, and it told investors customers now place orders 12 to 18 months ahead. Guidance implies roughly a $1.2bn annual run-rate.

MaxLinear, which designs communications chips for optical transceivers and broadband gear, grew 55.2% to $168.8m and returned to a GAAP profit. Its infrastructure segment rose 145% to about $85m, entirely on optical data-center signal processors, and it raised full-year optical revenue guidance by roughly $50m to $210-230m. September-quarter guidance implies a 25% sequential step up.

Applied Optoelectronics, the Texas maker of fiber-optic transceivers and lasers, reported its fifth consecutive record quarter on 6 August: revenue up 86.4% to $191.9m, 800G shipment volumes more than doubling sequentially, and September guidance of $255-290m. It is adding nearly 400,000 square feet in Pearland to build 800G and 1.6-terabit parts. The caution is in the margin: gross margin slipped to 27.7% from 30.3%, the thinnest in the group, and the operating margin was -12.9%. Consensus asks for $1.04bn this year and $2.80bn next against $343m delivered in the first half.

Semtech, which makes signal-integrity and long-range wireless chips, is the laggard: 15.9% revenue growth last reported quarter and operating income down 17.1%. It agreed on 13 August to sell its cellular module business to Compal for $62m, and analysts tie its August jump to a large cloud customer adopting its CopperEdge active copper cables.

The two that are genuinely rolling

Qualcomm is the only name where revenue, gross margin and operating income all fell at once: $9.95bn, down 4.0%; margin 53.1% from 55.6%; operating income down 41.1%. On 29 July it said its share of the coming iPhone would be materially below the prior 20% estimate, implying roughly a 50% sequential drop in Apple revenue into the December quarter. Its automotive business set a record at $1.6bn, up 61%, but that is not yet large enough to fill the hole.

indie Semiconductor, a $1.0bn automotive sensor and connectivity chipmaker, is not a data-center story. Revenue grew 24.0% to $64.0m on radar and vision ramps, but gross margin fell to 36.1% and the operating margin is -54.8%. Two sessions, up 18.8% and 17.8%, carry its entire month.

What the price level allows

Earnings multiples do not compare here — four of the seven have negative trailing earnings, and gross margins run from 27.7% to 63.0%. Against gross profit, MACOM trades at 38.0x trailing and 35.0x forward, versus 40.4x when this desk last measured it in May, while gross profit compounded 47%. Applied Optoelectronics is at 72.1x trailing and 41.3x forward, against 104.4x in May, on 71% gross-profit growth. Both are cheaper against a three-month-old anchor at a higher price. SiTime is the exception at 72.0x trailing and 38.8x forward, only 16.5% below its high after a 232% year. Qualcomm, at 18.5x trailing and 15.3x forward earnings with a 6.1% free-cash-flow yield, is the cheapest — on shrinking earnings.

Two outside forces sit under all of it. Morgan Stanley now projects hyperscaler capital spending near $800bn in 2026 and $1.2 trillion in 2027. And the Federal Communications Commission (FCC) is drafting a ban on new Chinese optical transceiver models for AI data centers, aimed at suppliers that hold over 60% of the 800G-and-above market — though Western replacements would need 12 to 24 months to scale and still depend on Chinese indium phosphide for the lasers inside.

The setup

Where it stands — Five of the seven guided the September quarter higher on data-center optics; only Qualcomm and Semtech reported falling operating income. Would confirm — MACOM's October-quarter revenue lands inside its $415-425m guidance with gross margin at 60% or better. Would invalidate — Applied Optoelectronics prints below the $255m low end of guidance, or MACOM's book-to-bill falls under 1.0. Watch next — MACOM reports fiscal fourth-quarter results in early November; the FCC aims to publish its draft transceiver rule before end-2026. Valuation — MACOM 38.0x trailing and 35.0x forward price-to-gross-profit, against 40.4x in May; SiTime 72.0x and 38.8x.