The company is rallying after its CEO announced the Robotaxi fleet in Austin will double next month, accelerating its autonomous driving ambitions. A major investor calls it a 'must-own' stock. Wall Street highlights the firm's rapid Full Self-Driving breakthroughs, leaving competitors far behind, and has ignited fresh price-target hikes. The company also launched a new 30-day free trial for its latest self-driving software in North America, a move seen as boosting adoption of its key technology.