An electric truck company that has yet to deliver a single vehicle already has a market value higher than industry stalwart Fiat Chrysler.

Since listing on the Nasdaq last week, the US start-up Nikola has seen its share price more than double, sending its market value to $26.3bn (£20.5bn).

The gains came after the firm announced on Twitter when it would accept orders for its pick-up truck.

The dramatic surge drew comparisons to more established rival Tesla.

Tesla has also seen its market value eclipse traditional competitors, despite having much smaller sales and a long history of financial losses.

On Twitter, Nikola chief executive Trevor Milton celebrated the share price gains, echoing the social media presence of Tesla boss Elon Musk.

Mr Milton, who is now a billionaire, said he had his sights set on overtaking Ford's best-selling F-150 pick-up truck, and promised to do his "part to be the most accessible and direct executive on Twitter".

What is Nikola?

Until recently, Nikola, which like Tesla takes its name from the inventor, had primarily focused its development on commercial trucks.

The firm, which is based in America's southwest in Arizona, has won financial backing from Bosch and companies connected to the family of Fiat's founder Giovanni Agnelli. It claims brewing giant Anheuser-Busch as a client.

It had raised about $500m prior to its listing, but the company has yet to generate any revenue. It lost more than $33m in the first three months of the year.

In gearing up for its listing, Nikola estimated its net worth at about $3.2bn. It raised more than $700m in the debut, which will go in part to building its manufacturing facility.

The firm, which has 250 employees, has said it has more than $10bn in pre-orders for commercial trucks and plans to start delivering trucks next year. It will start accepting orders for the Badger pick-up truck on 29 June.

Nikola's share price gains on Tuesday came as the Nasdaq hit another record. At one point, demand for Nikola shares pushed prices so high that the firm was worth above Ford's $28bn.