Shares in Donald Trump's social media company spiked after the president-elect again vowed not to sell his stake in the parent company of Truth Social and called for an investigation into "market manipulators or short sellers."

Trump Media's stock price increased by nearly 16 percent to $32 per share on Friday, as investors reacted to the news.

In interviews with ABC News before the election, some shareholders expressed optimism about the company's future if Trump won the election, in large part due to his potential ability to investigate and stop so-called "naked short sellers," who they blamed for the company's lackluster stock price.

Earlier this year, Trump Media's CEO Devin Nunes called for Nasdaq to investigate whether the company's stock price was manipulated by short sellers betting against the company without owning or borrowing shares.

“I’m very happy he’s the president and think he’ll do something about the short selling when he gets into office,” Todd Schlanger, a shareholder from West Palm Beach, told ABC News.

"The system seems kind of rigged," Todd Schlanger, a shareholder from West Palm Beach, told ABC News earlier this year. "Once he becomes president, I think he's going to fire the head of the SEC, and I think that's going to make a big change for the company and for all companies."

Shares in the company -- which some analysts saw as a bellwether for Trump's electoral odds -- have surged since late September when the stock traded as low as $12. As Trump's odds of winning the election improved, the stock's value tripled in October, trading at more than $50 per share.

But the company's long-term success remains uncertain, with the company losing more than $19 million during the last quarter while bringing in only $1 million in revenue, according to a recent SEC filing.

According to Similarweb, a data tracking site, the site only attracts 3.7 million unique monthly visitors, compared to rival X's 461.4M monthly visitors.

As Trump heads into office and the company's share price continues to surge, his 57 percent stake in the company is worth nearly $4 billion.