Tesla shares drop 5% in premarket after Cybercab robotaxi reveal fails to impress

Shares of electric vehicle maker Tesla sank after the company's long-awaited robotaxi event — where CEO Elon Musk  unveiled the firm's Cybercab self-driving concept car  — failed to impress investors.

Tesla stock was down 5% as of 4:45 a.m. ET in premarket trading on Friday.

- CNBC's Michael Bloom contributed to this report