Aehr Test Systems stands to benefit because testing is a bottleneck to scaling AI chips. Testing demand is about to surge. Investors did not question its price-to-sales ratio at 120, despite the current P/S objection. x.com  x.com 

Teradyne looks less dominant in CPO testing than expected after it acknowledged Advantest's capabilities on its earnings call. Per GF Securities, low TSMC SoIC yields have led the industry to cut 2026 CPO shipment forecasts, and Teradyne enters a 2H26 transition: Q2 guidance implies a 6% sequential drop, 55-60% of 2026 revenue falls in the first half, and it trades at 47x 2026 earnings. GF still sees long-term CPO upside, with 2027 CPO revenue possibly $800M. x.com  x.com 

Teradyne's test business is surging because rising AI chip complexity multiplies testing demand. Q2 revenue was a record $1.329 billion, up about 104% and above consensus, and Semiconductor Test revenue rose 128% to $1.122 billion. Management said AI is now its primary growth engine, contributing about $1.2 billion of Q2 revenue across compute, HBM and networking. More sophisticated GPUs, ASICs and HBM need far more testing, making its high-end ATE mission-critical. x.com 

Advantest beat because it simply grew at its own historical upcycle pace, which Wall Street underestimated. Revenue came in at ¥367B versus ¥336B consensus and a ¥360B forecast; analysts modeled just 2.3% sequential growth, while Advantest's median in an upcycle is closer to 10%. Earlier reports from Teradyne, TSMC and Disco had already signaled HBM4 pulling tester demand forward; Teradyne memory-test revenue below $170M or an AI mix under 65% would have broken that chain. x.com 

Teradyne's Q2 outlook coming in below its Q1 results is concerning when demand should be sky-high, and if later quarters look the same, its P/E would be too high to justify buying. x.com 

Teradyne supplies the testing behind the AI revolution, with fundamentals accelerating and technicals confirming. x.com 

FormFactor and Aehr Test Systems are favored because testing is the one non-optional part of the AI buildout. A single bad die ruins the whole package, so pricier chips mean more testing. FormFactor's probe cards touch every wafer; Q2 set records above a $1B run rate with gross margin over 50%, HBM4 is two-thirds of DRAM revenue and a new GPU program ships this half. Aehr guides fiscal 2027 revenue up 160-200% to $130-150M on a record backlog, plus a $22M AI follow-on order. x.com 

Advantest proved it deserves a premium valuation: its SoC tester market share rose from 56% in 2024 to 66% in 2025, widening its lead over Teradyne. It also received its first high-volume ATE order for silicon photonics. x.com 

Teradyne gains as AI chips grow more complex and expensive, because finding a faulty component before everything is packaged together becomes more valuable, and more AI chips mean more testing. It has just launched three new test instruments built specifically for AI and data-center chips. x.com 

Aehr Test Systems has become a key picks-and-shovels supplier to the AI chip boom, with its Sonoma platform the go-to system for reliability testing of high-power AI processors. On April 16, 2026, it announced a $41M follow-on order, its largest ever, from an unnamed hyperscale AI chip leader for custom AI ASIC testing, with revenue from fiscal 2027. Backlog doubled to $38.7M, second-half FY26 bookings exceed $92M, and FY26 should hit the high end of $45-50M guidance. x.com