Elon Musk unveiled a fleet of prototype Robotaxis — officially called the Cybercab — on Thursday.

Wall Street’s early reaction to Elon Musk’s robotaxi reveal? Disappointment.Shares in Tesla fell roughly 8% in morning trading following an event that was heavier on showbiz but lighter on business than investors had hoped after months of buildup.

Along with the robotaxi, Tesla is expected to provide updates on its humanoid Optimus robot — after all the event is titled “We, Robot,” a reference to Isaac Asimov’s seminal work I, Robot . Tesla might also show one of its mystery vehicles — a van or a cheaper car that could compete with China’s growing affordable EV market.