Shares of the Phoenix company at last check were off 20% at $38.92.
Nikola registered to offer millions of shares in an SEC filing after the market closed Friday.
"Practically speaking, this means that Nikola’s 24 million warrants are now exercisable, giving holders the right to buy NKLA shares for $11.50," analyst Emmanuel Rosner said in a note to clients,
"[And] this also registers the 53.4 million shares owned by (private investment in public equity) investors, enabling them to be traded on the market."
Rosner added that "the potential for a portion of these 77 million-plus shares to hit the market through early investors selling could create large technical selling pressure on NKLA stock."
"Once the stock eventually stabilizes," the analyst said, "we believe this could create a potentially attractive entry point for investors into NKLA, a rare pure play on zero-emission commercial trucks, whose adoption is poised to take off, driven by global regulations."
Last week, Rosner initiated coverage of Nikola with a hold rating. He praised the company's technological concept and market opportunity, but declined to recommend the stock, positing that the risks are not yet accounted for in Nikola's $17.6 billion valuation.
The filing is a preliminary prospectus that pertains, in part, to stock warrants that were issued as part of Nikola's initial public offering in early June.
Nikola went public through a merger with VectoIQ, a special-purpose acquisition company.
On Friday company Chairman Trevor Milton tweeted "S1 has gone affective finally!"
"All the fear mongering is insane and it'll be nice having the Pipe investors registered. It'll show who's long and who's not," Milton said. "The fear mongering can go away finally. It's difficult going ipo and after this, we're full steam ahead."
Milton added that "we'll be right back up in my opinion."
"It's the stock market. Of course you're going to have good days and bad days. We'll finally be through the worst of it imo," he wrote.