Shares of Trump Media shot up Friday, minutes after majority owner Donald Trump said he has no plans to sell his stake.

"I'm not selling," said the Republican presidential nominee, who will be free to start cashing in his nearly 57% stake in less than a week when a lockup agreement expires.

"I have absolutely no intention of selling," he said.

Trump Media shares rose by as much as 25% in intraday trading after Trump's comments to the press at his golf club in California on Friday afternoon. The stock ended the day up more than 11%, closing at $17.97 per share.

Trading activity for the stock was briefly halted twice due to volatility. Trump complained about the pauses later Friday in a post on Truth Social, the Twitter-like social media platform owned by Trump Media.

"Why is NASDAQ halting the sale of DJT? What right do they have to do this?" Trump wrote.

He threatened to hold the stock exchange, and possibly the Securities and Exchange Commission, "liable for doing what they are doing."

"If they do it again, we will move the stock to the New York Stock Exchange," Trump wrote, adding, "It is my intention to own this stock for a long period of time."

The threat came hours after Trump's remarks in California, where he said that Truth Social is "great for me" while noting that his stake in the company is worth more than $2 billion.

"But I don't want to sell my shares. I'm not going to sell my shares," he said.

"I didn't do it for the money. I did it because I really wanted to have a strong voice, and it's a great voice for me," he said. "And as long as my voice is on there, it's going to always be good."

The company's value initially soared when it began trading as DJT on the Nasdaq in late March after completing a merger with a special purpose acquisition company.

But the stock has plummeted in recent months, falling as much as 80% from its intraday peak.

"A lot of people think the reason it's down, is that a lot of people think I'm going to sell and if I sell, it wouldn't be the same," Trump said Friday.

Trump Media, which reported multimillion-dollar losses on scant revenue in its latest quarterly earnings reports, has said in SEC filings that Truth Social depends on Trump's continued popularity.

The company still boasts a market capitalization of more than $3.7 billion. Analysts have said that investing in Trump Media has become a way for Trump's fans to support him or bet on his political fortunes.

The company fell to its post-merger low point this week amid concerns that Trump might start selling his shares once he is free to do so.

— CNBC's Josephine Rozzelle contributed reporting.