Shares of Trump Media and Technology Group slid in midday trading Friday after President-elect Donald Trump transferred all of his shares into a revocable trust, according to a regulatory filing.

Trump transferred all of his nearly 115 million shares — worth around $4 billion on paper — in the parent company of social networking site Truth Social as a “bona fide gift” to the Donald J. Trump Revocable Trust, the Securities and Exchange Commission filing on Thursday said. Trump’s shares amount to more than half of the company’s stock.

It’s not clear why Trump transferred the stock. Donald Trump Jr. is the sole trustee and has sole voting and investment power over all securities owned by the trust.

Trump Media shares were down about 2% at midday, to $34.68 each. At one point Friday, they were down around 6%.

Trump Media shares have been extremely volatile since the company began trading in March. They reached intraday highs close to $80 on the first day of trading, then slumped to all-time lows in September when Trump and other insiders were finally allowed to sell shares after standard lock-up agreements expired. Trump has not sold any shares in the company.

The company’s stock price has fluctuated wildly on news — good and bad — related to Trump. They tumbled after Trump’s conviction in a hush money trial in May, then surged after the first assassination attempt on Trump in July. They surged again after he won re-election in November, even as the company reported a $19.2 million third-quarter loss.

Trump created Trump Media after he was banned from Twitter and Facebook following the Jan. 6, 2021, Capitol riot.