A quiet, mixed robotics session — battery and test names firmed while a software-sector selloff took the simulation layer lower.

Robotics had a muted, two-sided session against a market that fell broadly on higher oil and firmer yields (S&P 500 −0.58%). The leader was Amprius (AMPX), up only 5.1% to $10.39 — a modest print by the day's standards elsewhere and, notably, a bounce in a stock still down roughly 54% over the prior 90 days. Amprius maps the batteries-and-power chokepoint: its silicon-anode SiCore and SiMaxx cells feed the actuation and endurance budget of mobile robots and UAS, and the company recently raised full-year revenue guidance to at least $140M on drone and defense demand, with a run of investor presentations scheduled through September. There was no single catalyst on Tuesday; the move was sentiment firming into those events rather than fresh news.

The laggard was PTC (PTC), down 5.5% to $133.26, on the simulation-software chokepoint — the CAD/PLM digital-thread layer that designs and validates robotic cells before they are built. The decline was not company-specific: a wave of selling hit the enterprise-software group and dragged PTC down with its peers, a sector rotation rather than a fundamental crack in the design-tools thesis.

Elsewhere the basket was mixed. Teradyne (TER) rose 4.2% to $372.06 on the platforms-and-integrators chokepoint — the automated test and cobot arm that gates how fast robots can be manufactured and qualified — and Tesla (TSLA) added 4.0% to $368.16 on the actuators/motors and tactile-sensing straits that underpin its Optimus program. Enovix (ENVX) climbed 4.5% to $3.47 alongside Amprius on batteries-and-power, and Qualcomm (QCOM) added 3.2% on edge compute. The Japanese precision-motion complex — the harmonic-drive gears and linear-motion bearings that remain the industry's tightest mechanical chokepoint — softened on its own Tokyo session, a reminder that this supply base trades a day out of phase with the US tape.

The catalysts that matter are structural and back-half weighted. ABB's robotics divestiture to SoftBank is expected to close around end-September, reshaping ownership of the industrial-arm base. RoboBusiness runs Oct 19–21 in Santa Clara, the Humanoids Summit follows Dec 1–2, and NVIDIA's GR00T N2 humanoid foundation model is targeted for availability by year-end — the software layer that could compress the sensing-to-actuation gap. On the supply side, the DFARS ban on Chinese-melted or -fabricated NdFeB and SmCo magnets in defense systems takes effect Jan 1, 2027, the date that decides how tight the rare-earth-magnet chokepoint gets for every actuator.