Jefferies ( JEF) analysts called Tesla’s $30,000 robotaxi, dubbed the Cybercab, a “toothless taxi” in a note to investors Friday morning, adding that Tesla has “ambitious targets" with “little evidence of feasibility.” “We believe TSLA potentially underappreciates the obstacles to scaling a robotaxi fleet,” they wrote.

"Waymo is now hosting 100k rides per week in major cities, so we expect more from TSLA's demo," Wells Fargo analyst Colin Langan said.

Tesla shares' 8.8% decline Friday took away $67 billion in market capitalization from the elecric-car maker, the biggest one-day vanishing of value for the stock since July 24, according to Dow Jones Market Data.