Tesla Motors (TSLA 1.85%) was one of last week's biggest winners, tacking on another 14% to its breathtaking year.

The company behind the all-electric Model S sedan has seen its stock soar 379% in 2013, thrilling the longs while leaving the naysayers dumbfounded.

Is Tesla really worth its nearly $20 billion market cap? That seems like a steep sticker for a company that delivered just 5,150 cars in its latest quarter, but there's more to Tesla than what you see in the rearview mirror.

One of the drivers behind last week's pop was Tesla's move to file an application for the Model E trademark. CEO Elon Musk has discussed getting a more economical electric vehicle on the market as early as 2017, and Model E would seem like an obvious name for it. Model S stands for sedan. Next year's Model X stands for crossover. Is there a better letter in the alphabet to mark the entry into the economy market than E?

These are interesting times for Tesla and Musk. 

The latest television spots for General Motors (GM 4.37%) position the Chevy Volt as "America's best-selling plug in," but there's more to moving cars than a number. There were 1,788 Volts sold last month, more than Tesla's monthly average this past quarter, but let's go over a few key points.

  • Tesla's sales have been held back by supply, and that's something that should find Tesla's Model S ahead of the Volt and Nissan Leaf in the next quarter or two as it ramps up production capacity.
  • Tesla's profitable. Yes, GM is in the black, but who knows how much money it's losing on the Volt? 
  • Tesla's Model S costs between two and three times the going price for the Volt. In other words, the Volt may be the top seller over the past year based on unit volume, but Tesla's the one bringing home the revenue.
This doesn't mean that Tesla isn't overvalued these days. The point here is that it's misleading to judge Tesla based on past financials.

Tesla's sitting pretty these days. Analysts see revenue climbing just 37% higher next year, but they see profitability more than tripling to $1.72 a share. Yes, there's a limit to the number of people that can fork over more than $70,000 for a new car, but Tesla's laying down the groundwork of charging stations and dealerships that will light up the roadways the moment that its more accessibly priced Model E hits the market. 

Tesla's the brand that everyone will want in the future with the stock that everyone wishes they had bought in the past.