What happened

Shares of electric truck maker Nikola (NKLA 0.76%) opened higher again on Tuesday morning, a day after doubling in value, despite a Bloomberg report that called the company's valuation into question.

Although the rally fell back as the session went on, trading in Nikola's shares opened at $93.13 on Tuesday morning, up about 27.1% from Monday's closing price. 

So what

Nikola's stock surged into the stratosphere on Monday, closing up over 100% after founder Trevor Milton tweeted that the company will soon begin taking reservations for a new electric pickup truck called the Badger. 

A silver Nikola Badger electric pickup truck.

On paper, Nikola's Badger pickup looks promising. But it's a long, long way from being real. Image source: Nikola.

Is this wild run justified? Not yet, certainly. As a Bloomberg report noted on Tuesday morning, this is a company with no revenue, it won't hit $1 billion in sales until at least 2023, and it can't ship the Badger pickup until (and unless) it signs a partnership deal with a major automaker with the capacity and skills to build the truck.

Nikola (and its fans) make much of the fact that the company has taken 14,000 "reservations" for its electric semis. But as Bloomberg points out, those reservations aren't binding contracts and didn't require a deposit. It's impossible to know how many will convert to actual sales. 

So why was it rallying again as the market opened on Tuesday? Good question. 

Now what

Here's what Milton, now the company's chairman, had to say after yesterday's epic run. 

I have on occasion chided Tesla (TSLA 1.85%) CEO Elon Musk for hubris, but this is something else. Right now, Nikola makes Tesla look like a value stock. 

Milton and his team would be well advised to log off Twitter, stop watching the stock, and get to work. If you want to build something of enduring value, you need to show us, not just tell us.