(Reuters) - Shares of Donald Trump's media and technology firm fell as much as 12% on Monday, extending a selloff that has now reduced the value of his stake in the operator of Truth Social to $2.9 billion.

After its strong debut in late March, investors have soured on Trump Media & Technology Group ( DJT ) after the company disclosed millions of dollars in losses earlier this month and said it would struggle to meet its financial liabilities.

The company's stock closed 8.4% lower at $37.17 on Monday, a far cry from the record high of $79 it had notched during its debut on March 26. It is down about 40% so far in April.

The declines are reducing a potential windfall for Trump who could sell his shares to raise money for his 2024 presidential campaign and legal expenses, although lock-up restrictions for six months could prevent him from selling or borrowing against his shareholding.

Former U.S. President Trump - who owns about 78.75 million shares in the company - has seen a sharp slide in the valuation of his stake from around $6 billion last month.

The market value of whole of Trump Media & Technology Group ( DJT ) is now below that figure, at about $5.55 billion.

But the declines are welcome news for short-sellers who have suffered hefty losses on the stock so far this year.

Trump Media & Technology Group ( DJT ) has a short interest of about 4.75 million shares, or 12% of its free float, according to analytics firm S3 Partners.

Monday's decline meant those betting against the stock made about $16 million in market-to-market profits, though those shorting the stock are still down 69% for the year.

"DJT's recent price weakness has offset the huuuuge financing costs short sellers are incurring and keeping many of them in the trade," said Ihor Dusaniwsky, managing director of predictive analytics at S3 Partners.