You may think the company's future isn't worth a $56 billion present value, but comparing Tesla's historical production against Ford and GM is completely missing the point.
That would be like comparing Google's revenue in 2004 against its competitors in the advertising industry.
Investors who bought Google's IPO were valuing the company's potential in 2014 and 2024, not its minuscule market share in 2004.
Google's 2004 IPO valued the company at $23 billion, twice as much as WPP Group even though WPP had much higher revenue than Google.
Today Google is worth 35 WPPs, and Tesla investors think it could be worth multiple GMs and Fords ten years hence.