Twelve names cleared the screen: revenue-stage companies whose filings tie a specific product line to hyperscaler or AI data-center demand, at small-cap scale, ranked below by what the numbers show as of the September 22 close. The four that matter most are the ones with the most direct capex linkage — two bitcoin-to-AI conversions (APLD, IREN) and two component suppliers one layer down (NVTS in rack power, AAOI in optics). A strict $5B cut keeps NVTS and AAOI; APLD and IREN have already re-rated above it on the same thesis and stay in because nothing else on the list has exposure this direct. The other eight are real but second-order — profitable component and electrical names where AI is one demand driver among several — and are covered briefly after the table.

By name:

• Applied Digital (APLD) — BTC sites pivoted to AI HPC. The company has repositioned from blockchain hosting into purpose-built HPC data centers; its Ellendale, North Dakota campus is being built for hyperscale-class tenants under long-term hosting arrangements. FY2025 revenue $215.5M on a 10.5% gross margin — the margin is the tell: conversion capex runs through cost of revenue before HPC leases start paying. The thesis is lease signings, not the current P&L.

• IREN (IREN) — Same pivot, NVIDIA partnership. FY2025 revenue $501.0M, +167.7% YoY at a 68.3% gross margin — the mining fleet still funds the AI-cloud build, and the company was named an NVIDIA Preferred Partner for its AI cloud offering. Operating margin is only 4.4% because GPU depreciation now sits in the cost base. Largest and most re-rated of the four.

• Navitas Semiconductor (NVTS) — GaN power for AI server PSUs. Q2 2025 revenue $14.5M, −29.2% YoY : the consumer/mobile GaN business is rolling off while the company pivots to high-power markets — AI data-center power supply units and 800 V DC architectures developed with hyperscalers. Gross margin 16.1% , operating margin −149% . Smallest revenue base, most direct exposure to rack power density, least evidence yet in the numbers — this is the optionality name.

• Applied Optoelectronics (AAOI) — Optical transceivers for AI clusters. Q2 2025 revenue $103.0M, +137.9% YoY , with datacenter transceiver revenue growing on 800G qualification at a hyperscale customer. The in-house laser fab in Sugar Land, Texas is the differentiator — most competitors buy their lasers. Gross margin 30.3% , still an operating loss (−15.5%) as capacity is added ahead of volume.

The other eight, in one line each:

• Vicor (VICR) — 48 V power modules for accelerator boards; Q2 revenue +64% but a chunk of that is a one-time licensing settlement, so the 65% gross margin overstates the run-rate. Real AI exposure, lumpy revenue.
• Semtech (SMTC) — CopperEdge and LPO drivers for short-reach AI interconnect; Q2 FY2026 revenue +19.6% , 52% gross margin. Data-center is the growth segment inside a diversified analog business.
• Camtek (CAMT) — inspection for HBM and advanced packaging; +20.2% revenue , 25.9% operating margin. The most profitable AI-linked name here; exposure is to memory capex, one step removed from the hyperscaler.
• Bel Fuse (BELFB) — power and connectivity components; +26.4% revenue , 15.5% operating margin, filings flag AI-driven IC lead-time extensions. Diversified, no single-customer risk.
• Powell Industries (POWL) — switchgear and e-houses; data-center orders are a growing slice of a utility- and oil-and-gas-heavy backlog. Revenue flat YoY , 21% operating margin.
• IES Holdings (IESC) — data-center electrical contracting; +15.8% revenue , 12.6% operating margin. Labour-based, so margin ceiling is structural.
• Penguin Solutions (PENG) — AI/HPC cluster integration; +7.9% revenue , 3% operating margin. Integration is low-margin work; the exposure is real, the economics are not.
• Aehr Test Systems (AEHR) — wafer-level burn-in; revenue −15% as SiC demand faded before the AI processor burn-in business scaled. On the list for optionality only.

Key risk to flag: none of the four lead names earns an operating profit, and all four are priced on hyperscaler capex guidance (Microsoft, Amazon, Google, Meta) holding its current trajectory. What would change this view: a lease that does not close at APLD or IREN, or a capex cut at any of the big four, hits the pre-profit names first and hardest. NVTS is the outlier — a disclosed design win in an 800 V AI-factory power architecture would re-rate it independently of the others.

Sources: Applied Digital Form 10-K, FY2025 (fiscal year ended 2025-05-31); IREN Limited Form 10-K, FY2025 (fiscal year ended 2025-06-30) and Q4 FY2025 results release; Navitas Semiconductor Form 10-Q, Q2 2025; Applied Optoelectronics Form 10-Q, Q2 2025; latest quarterly filings before the run date for Vicor, Semtech, Camtek, Bel Fuse, Powell Industries, IES Holdings, Penguin Solutions and Aehr Test Systems — for revenue and margins. Closes from price_volume_history as of 2025-09-22. Candidate set from company_search and news_search.