Tesla (NASDAQ: TSLA) and SpaceX announced on August 6 that they will jointly spend $16.8 billion on the first phase of Terafab, a semiconductor manufacturing plant located in Grimes County, Texas. The plant is being built to produce chips primarily intended for products that have not yet reached mass-market scale, including Tesla’s Optimus humanoid robot and Cybercab autonomous vehicle. For investors watching Tesla’s valuation and cash deployment, Terafab represents one of the most visible and concrete signals yet of just how seriously Elon Musk’s companies are treating the autonomy and robotics transition as a near-term industrial reality.