The share price of Trump Media closed trading Monday more than 12% higher, continuing a stunning rise that began in mid-April.
The DJT ticker ended the day at $46.69 per share, up by $5.15, a gain of 12.4%.
Trump Media owns the Truth Social app frequently used by the company's majority shareholder, former President Donald Trump, who is also the presumptive Republican presidential nominee this year.
"TRUTH SOCIAL IS THE REAL VOICE OF AMERICA!!!" Trump wrote in a post on the site earlier Monday.
The company began public trading on March 26 with a price of more than $70 per share. Over the next several weeks, share prices cratered, ending up with a low closing price of $22.80 on April 16.
Since then, Trump Media shares have more than doubled in price, adding billions of dollars to both the company's market capitalization and the ex-president's stake.
The gains occurred without significant news about the company's bottom line improving.
But Jay Ritter, a business professor at the University of Florida, said that the recent bump in Trump Media's stock price might be the short-term result of recent statements and regulatory filings by the company targeting short sellers.
"In the last week or so the company has informed its shareholders how to make it difficult to loan their shares to short sellers, and it is possible that the number of shares available to short has decreased, increasing the [cost] borrowing rate for short selling," said Ritter, who is an expert on initial public offerings.
"And it is possible that some of them [short sellers] have cut back on that."
Ritter also that "there might be some" short squeeze occurring, in which short sellers, who are betting that the share price will drop, are forced to repurchase Trump Media shares to replace the stock they borrowed to sell short. Such repurchases can drive the price of shares, which in turn increases pressure on short sellers to buy stock to cover their positions, which also leads to price bumps.
Earlier Monday, Trump Media issued a press release that essentially underscored previously released information to shareholders advising them on how to avoid having their stock shares loaned out for use by short sellers to bet the price drops.
The company last week asked Republican committee chairs in the House of Representatives to investigate what it claimed was potential manipulation of Trump Media's share price by short sellers.
Ritter said that request, which has yet to be acted upon, also could be helping drive up the share price.
But regardless of how much the attack on short sellers is affecting the price, Ritter said that Trump Media remains a "meme stock," whose market valuation bears little if any relationship to its underlying business, and future business prospects.
Trump Media has more than $200 million in cash, but its social media business last year booked $58 million in losses with revenue of just $4.1 million.
But the company has as its effective face Donald Trump, whose political supporters are among the small shareholders helping to bolster the stock price.
"With these meme stocks it's really difficult to predict what's going on on a daily or weekly basis," Ritter said.
"Whether we're dealing with a price of $32 per share a week ago, or $46 now, we're quibbling about whether the stock is overvalued by 1,000% or 2,000%," he said.
Ritter noted that Trump Media's market capitalization, when factoring in 36 million extra shares Trump was recently granted as a result of the stock price staying above $17.50, is about $8 billion.
"A company with less than $5 million of annual revenue and losing lots of money and doesn't seem to have business plans that are going to generate a lot of growth," Ritter said. "The company might be worth a couple of hundred million dollars, but $8 billion seems like on the order of 2,000%" of what it should be worth according to traditional metrics, he said.
Ritter expects Trump Media's share price to eventually plummet to the low single digits.
When meme stocks "get fantastically overvalued," he said, "it's easy to predict with a high degree of confidence that the long-term returns are going to be pretty bad."
This is developing news. Check back for updates.