Born-again EV company Fisker is somehow worth nearly $3 billion now

Excitement over Tesla is leading to some pretty crazy market movements after the company became the most valuable automaker in the world. Case in point, the relaunched EV maker Fisker is now somehow worth $2.9 billion even though it hasn't made a single car or offered much detail on how it plans to do so.

The valuation is possible because Fisker announced yesterday that it will go public by merging with an existing public company called Spartan Energy. That company's stock surged 29 percent on the news, and the plan is to raise an additional $1 billion from the public markets in order to fund the development of the first car. All in, the combined value of the company will be nearly $3 billion.

Neither Fisker nor Spartan Energy currently make any products or generate any revenue. Spartan is a "blank check" public company, funded by private equity, with the sole purpose of acquiring another business. Fisker, meanwhile, is a born-again version of Fisker Automotive, which went bankrupt in 2014 after selling just 2,000 of its luxury Fisker Karma electric cars. The founder Henrik Fisker hopes a second attempt, the Fisker Ocean SUV, will have more success when it launches in 2022.

Lots of questions — Investing in Fisker in hopes of riding the hype wave behind Tesla seems like a dubious proposition. Tesla has defied all expectations to pump out nearly 100,000 cars a quarter while Fisker, like most other EV startups, basically just has mock-ups.

Fisker has revealed little else about the Ocean, like pricing or who's going to build it – the company doesn't own a factory, saying instead that it will design the car and outsource production to someone else. We also don't know who will supply crucial parts like the battery, the technology and supply chain for which Tesla has perfected over years and billions of dollars in investment. Fisker has apparently developed its own battery technology to rival Tesla, though it's made some quite overambitious claims that it's had to walk back, like saying its batteries would get 500 miles of range.

Another car startup Nikola recently went public through a similar maneuver and shot up in value. That company is planning on making hydrogen-powered big rigs. Its promises have also raised questions.

Tesla is an exception to the rule — Needless to say, if you invest in the new Fisker, you're gambling. The reward of getting in on the ground floor could be high if Fisker is able to get its car to market and scale production, but no EV upstart has really been able to accomplish that besides Tesla. Remember Byton? Or maybe Faraday? Heck, even Dyson raised the white flag after plowing £500 million (~$627 million) into its own EV effort. Existing automotive giants are starting to catch up in EVs but they already benefit from vast supply chains and huge scale, selling millions of cars annually. Sure, Fisker made cars once, but they cost over $100,000 and weren't very good. Becoming anything besides a niche player will require selling lots of cars — and Fisker has never done that.

It'd be great to see any company pushing for renewables succeed, and the original Fisker Karma was undeniably good looking. But many unanswered questions makes us wary of Fisker. What's to say it won't walk back even more claims? Now that it will be a public company, investors have to be wary about investing based on what it says. Don't be confused; Fisker is not a comparable investment to Tesla.