Trump Media & Technology Group (TMTG) announced losses of more than $58 million (£46 million) in 2023, which sparked the decline.
The business issued a warning, stating that it would be difficult for it to pay its debts in the future.
When the social media platform debuted in New York last week, its shares ended the day at $58 (£46).
But after the most recent announcement, they dropped 21% by Monday’s close to about $49 (£39) – nearly $1 (80p) less than the offering price.
With 78.75 million shares in the corporation, Mr. Trump could be able to sell his stock and use the proceeds to help him through his ongoing legal and financial troubles.
His shareholding was worth almost $6 billion (£4.8 billion) at its highest point last week; it is currently valued at about $3.8 billion (£3 billion). For a period of six months, he cannot sell or borrow against any of his shares.