Robotics split on a chip-led risk-off — rare-earth, edge-AI and speculative names fell 4–10% — while the actuator and motion core held green.

Enovix (ENVX) led the robotics basket Monday, up 5.3% to $2.59 on the batteries-and-power rung — a bounce in a beaten-down cell maker with no company news behind it. The genuine strength sat in the mechanical and sensing core: Moog (MOG.A) +2.4% to $371.76 on actuators and motors, THK's ADR (THKLY) +1.9% to $22.05 on linear motion, and Novanta (NOVT) +2.7% to $145.03 on precision sensing. These are the rungs a humanoid can't be built without, and the ones with the least China-competition exposure on a China-driven risk-off day.

The laggard was Serve Robotics (SERV), down 10.0% to about $3.92 on the platforms-and-integrators rung, with no company-specific catalyst in the session — the speculative delivery-robot name was simply the sharpest casualty of a momentum unwind that hit the market's most sentiment-driven robotics bets. Symbotic (SYM) -4.3% to $40.78 and Teradyne (TER) -4.7% to $383.85 fell with it on the same rung, the warehouse-automation and test names that trade on AI-capex optimism.

The chip-exposed rungs took the China-competition selloff directly. On sensing and touch: STMicroelectronics (STM) -3.0% to $50.48 and Allegro (ALGM) -5.0% to $33.79; on edge-AI compute, Ambarella (AMBA) -3.9% to $64.81. The rare-earth-magnets rung — the NdFeB bottleneck shared with drones — was the worst hit: MP Materials (MP) -6.0% to $43.36 and USA Rare Earth (USAR) -5.9% to $11.82, with battery peer Amprius (AMPX) -6.0% to $8.87. Tesla (TSLA), the humanoid wildcard spanning the actuator and sensing rungs, slipped 1.2% to $378.03.

RoboBusiness (Santa Clara, Oct 19–21) is the next hard catalyst — the industrial-humanoid showcase where the actuator, gearing and sensing rungs that held green Monday demonstrate the integration progress the tape wasn't pricing. Beyond it, Tesla's Optimus V3 reveal and Fremont production start remain the single largest demand signal for the precision-gears and actuator rungs; no firm date has held.