What happened

Shares of embattled electric-truck start-up Nikola (NKLA -2.41%) opened lower again on Thursday, after a once-bullish analyst cut his rating and price target for the stock.

As of 10 a.m. EDT, Nikola's shares were down about 13.5% from Wednesday's closing price.

So what

Nikola's stock has been under intense pressure since short-selling firm Hindenburg Research released a report on Sept. 10 alleging that the start-up misled investors. The company's failure to respond convincingly to the allegations -- and the abrupt departure of founder Trevor Milton early Monday morning -- have only accelerated the stock's downhill slide.

Thursday morning brought a new challenge for the stock. Wedbush analyst Daniel Ives, who had been upbeat about the company's prospects not so long ago, cut his rating on Nikola to underperform, from neutral, and his price target all the way to $15 from $45.

A red Nikola Two electric semi is shown hauling an Anheuser-Busch trailer.

Nikola has a long way to go to regain credibility with investors, a Wall Street analyst wrote on Thursday. Image source: Nikola.

Ives wrote that while he still thinks the company's ambitions for battery-electric and hydrogen fuel-cell semitrucks are attainable, he now has "serious concerns" about the company's ability to execute its growth plan on its hoped-for schedule. Ives feels that Milton's departure changed the investment story, increasing the already-significant risks that the company may not be able to deliver on its plan. 

Until the company answers the questions raised by Hindenburg's report, Ives wrote, a "dark cloud" will hang over Nikola's stock -- and by extension, the company. That's why the sell-off was continuing on Thursday morning. 

Now what

On the one hand, I have maintained -- and still maintain -- that there's a business here despite the serious allegations against the company. Nikola has money in the bank, a credible management team, and key partnerships with General Motors, auto supplier Robert Bosch, and CNH Industrial, the parent company of heavy-truck maker IVECO. In theory, at least, it could proceed with its go-to-market plan, in hopes of rebuilding credibility with investors over time. 

On the other hand, we learned yesterday that energy major BP put partnership talks with Nikola on hold after the Hindenburg report was published. Clearly, the business world is now wary of the company, which will complicate negotiations with other potential partners and could be a big problem if and when Nikola needs to raise additional capital in the future.

Long story short: Nikola doesn't seem likely to go completely bust, at least not any time soon. But the story has changed, and I think any auto investors who are considering Nikola's beaten-up shares would do well to wait until that dark cloud clears enough for us to see what's left.