Rejected by more than two dozen bond companies, Donald J. Trump has so far been unable to come up with the nearly half-a-billion dollar penalty owed by Monday in his civil fraud trial.

Just days before the deadline, the former president’s social media company completed a merger — a move that is poised to pump an estimated $3 billion into Mr. Trump’s coffers. That is more than enough to cover the $454 million penalty that he owes to the state of New York, but the merger restricts him from selling his shares for six months, or using them as a collateral against a loan.