(Reuters) -Shares of Trump Media & Technology Group fell 5% on Friday as the Truth Social parent extended this week's steep selloff after a lock-up on insider sales expired.

Shares of the $2.9 billion firm, which is 57% owned by U.S. Republican candidate Donald Trump, have slumped about 18% in the past four straight sessions and is down about 80% from their April peak.

Trump, whose stake is currently worth $1.6 billion, said last week he does not plan on selling his shares, turning the focus to other major stakeholders who could sell shares.

United Atlantic Ventures and Patrick Orlando, whose fund, ARC Global Investments II, sponsored the blank-check company that merged with Trump Media in March, together own about 11% of Trump Media shares.

With only a third of Trump Media's shares currently available for trading, any stake sale is expected to rock the shares.

"Not only will the possible new selling activity affect DJT's stock price directly, it will also increase DJT's stock lending pool which will facilitate increased short selling in the stock," said Ihor Dusaniwsky, managing director of predictive analytics at S3 Partners, in a note on Thursday.

Trump Media and Orlando did not immediately respond to a request for a comment.

Shares of the loss-making company were last trading at the lowest since their March debut at $14 as restrictions on insider sales expired Thursday after markets closed.

(Reporting by Medha Singh in Bengaluru; Editing by Saumyadeb Chakrabarty)