The four-stock "AI2: Robotics & Physical AI" bucket — Symbotic (SYM), Rockwell Automation (ROK), Cognex (CGNX) and Teradyne (TER) — has returned roughly 80% on average over the past year, a number that reads like a broad physical-AI re-rating. It isn't. Teradyne, which makes automated test equipment for chips and also owns the Universal Robots and MiR collaborative-robot brands, is up 248% over the same stretch, single-handedly dragging the average; Cognex, which sells machine-vision sensors and software used in factory and logistics automation, is up a more modest 58%, and Rockwell Automation, the industrial-controls and automation-systems maker, is up 37%. Symbotic, which builds robotic warehouse-automation systems and derives more than 84% of revenue from Walmart, is down 24% over the same year — the opposite direction from the label the bucket carries.

The chip-test cycle, not robotics

Teradyne's Q2 2026 revenue hit a record $1.33B, up 104% year over year, and the company beat its own guidance for a second straight record quarter. That was driven almost entirely by Semiconductor Test, which posted $1.12B, up 128% YoY and 84% of total sales, on HBM and DRAM test demand. The robotics arm did grow — Universal Robots and MiR posted a first-ever $100M quarter, up 33% YoY — but at roughly 7.5% of revenue it is a rounding error next to the test business. Business momentum genuinely explains the move, but the price has run ahead: Teradyne trades near 81x trailing earnings and 18x trailing sales, both expanding even as an earnings-tracking recap flags sequentially declining Q3 guidance after two record quarters — growth confirms, but the multiple leaves little room for a stumble.

Cognex and Rockwell: a genuine, if pricier, industrial turn

Cognex's Q1 2026 revenue grew 24% YoY, with logistics posting its ninth straight quarter of double-digit growth; it has held a sustained uptrend on its price chart since late April, with its next print due Aug 5. At roughly 75x trailing earnings, the user's own research notes call the multiple a stretch that needs sustained double-digit EPS growth to justify, and flag Keyence and Chinese entrants gaining share in North American machine vision — a risk the price trend doesn't capture. Rockwell posted 9% organic sales growth with North America organic orders up 10% and a longer-cycle book-to-bill of 1.07, against a US manufacturing PMI that sat at 53.8 in July — expansionary, not soft. Rockwell reports Q3 on Aug 4, with book-to-bill again the number analysts are watching. Both names confirm on fundamentals; both are also priced near the high end of their own multiple history.

The real divergence: Symbotic and Ouster

Symbotic is the outlier. Its backlog stood at $22.7B and revenue grew 29% YoY with a first double-digit EBITDA margin, guidance for its Aug 5 print calls for $700-720M revenue — yet the stock has fallen 24% over the year and its trend has read persistently negative since May, its multiple compressing from over 14x to under 10x sales on unchanged or improving fundamentals. The overhang is more than 84% Walmart revenue concentration and a still-live SEC investigation tied to a 2024 revenue-recognition restatement. Ouster, the overlapping lidar-sensor maker paired with Cognex in the vision bucket, shows the same tape-lags-reality pattern in reverse: Q1 2026 revenue grew 49% YoY but gross margin fell to 43% from 60% the prior quarter, even as its price trend has not yet turned down despite a 22% monthly decline.

The setup

Where it stands — Cohort gain is concentrated in Teradyne's chip-test cycle; Symbotic diverges from its own improving fundamentals, trading down while backlog and margins rise. Would confirm — Symbotic's Aug 5 print shows backlog growth continuing and Walmart concentration declining toward diversified customers. Would invalidate — Teradyne's Q3 guide confirms a sequential revenue decline with Semiconductor Test book-to-bill falling back toward 1.0. Watch next — Cognex and Symbotic both report Aug 5, 2026; Rockwell reports Aug 4, 2026. Valuation — TER ~81x trailing P/E; CGNX ~75x; ROK ~50x, near its historical high; SYM unprofitable at ~9.9x trailing sales, down from 14.5x in May.