Rivian is trading at about 2.5 times Tesla's valuation based on this cutting-edge metric

A Rivian R1T electric pickup truck during the company's IPO outside the Nasdaq MarketSite in New York, on Wednesday, Nov. 10, 2021.
Bing Guan | Bloomberg | Getty Images

Newly public electric-vehicle maker Rivian Automotive is already trading at more than double Tesla's lofty valuation, according to one analyst's unconventional valuation method.