According to people familiar with the discussions, executives at an obscure Miami investment firm began scheming ways to make money off of the deal months before it was made public.

In October, it was announced that Mr. Trump would be merging with a special purpose acquisition company. The SPAC's share price went up.

According to three people familiar with the firm's internal discussions, employees at the Miami investment firm were aware of the pending deal over the summer. According to two people, Rocket One officials discussed investing in the Digital World Acquisition Corporation in order to profit from the soon-to-be announced transaction with Trump Media & Technology Group.

In the days before the Trump Media deal became public, there was a surge in trading in warrants, which entitle investors to buy shares of Digital World at a preset price in the future.

The merger of Digital World and Trump Media is being investigated by federal prosecutors and regulators. A federal grand jury in Manhattan has subpoenaed information about Rocket One, according to a recent regulatory filing.

The scope of the investigations is not clear. Representatives of Mr. Garelick and other people denied doing anything wrong.

There was no advance knowledge of the merger between Digital World and Trump Media according to a lawyer for Rocket One. Any assertion that is not true is false.

Representatives for the Securities and Exchange Commission and the U.S. attorney's office in Manhattan refused to comment on the case.

ImageThe Securities and Exchange Commission is considering whether to block the merger of Mr. Trump’s business and a financing company.
The Securities and Exchange Commission is considering whether to block the merger of Mr. Trump’s business and a financing company.Credit...Andrew Kelly/Reuters
The Securities and Exchange Commission is considering whether to block the merger of Mr. Trump’s business and a financing company.

Representatives for Mr. Trump did not reply to questions. The company said in a news release that neither Mr. Trump nor the company's CEO received subpoenas. The men were only identified by their jobs.

The investigation into unusual trading in Digital World securities is another blow to Mr. Trump's social media venture.

Digital World's disclosures about the merger talks with Trump Media are under investigation. The Securities and Exchange Commission is considering blocking the merger. It would deprive Trump Media of over a billion dollars if the deal doesn't happen.

There is little public information about Rocket One, which has fewer than 10 employees and has made about 20 early-stage investments over the past decade, according to a review of archives and an analysis by a data company. The name of the company appeared in a regulatory filing.

According to two people familiar with the discussions, Mr. Garelick mentioned the possibility of a deal with Trump Media to some employees. One of the people said that an employee of Rocket One was told to perform a financial analysis of Digital World.

Carl Schoeppl didn't want to comment. In an email, Mr. Schoeppl said that they reserve the right to assert claims for defamation for any article that states, suggests, and/or otherwise implies that Bruce J. Garelick committed insider trading.

The Digital World warrants were snapped up by traders before the merger with Trump Media was announced. The stock and warrants of Digital World increased in value the next day, with the stock increasing 350 percent and the warrants increasing 1,300 percent.

If the merger is completed, Digital World will have access to an additional $1 billion from other investors.

The only product of Trump Media is Truth Social. It has become the main way for Mr. Trump to communicate with his supporters. He used Truth Social to blast the congressional committee that is investigating the attack on the U.S Capitol. As Mr. Trump ponders another White House bid, the platform could become more important.

ImageAndy Litinsky, left, with Wes Moss, contestants on “The Apprentice,” received subpoenas from a federal grand jury.
Andy Litinsky, left, with Wes Moss, contestants on “The Apprentice,” received subpoenas from a federal grand jury.Credit...Dimitrios Kambouris/WireImage for Vogue, via Getty Images
Andy Litinsky, left, with Wes Moss, contestants on “The Apprentice,” received subpoenas from a federal grand jury.

Federal authorities are still investigating whether the leaders of Digital World and Trump Media started talking about a merger before the company went public. Digital World did not identify a merger target at the time of its initial public offering. According to The New York Times, talks between Mr.Orlando and Trump Media officials were already under way.

Digital World would have been in violation of S.E.C. rules if they hadn't disclosed the merger talks to investors.

Grand jury subpoenas are an indication of a criminal investigation.

According to people briefed on the matter, two former contestants on Mr. Trump's show were subpoenaed by the grand jury.

The two men pitched the idea of a Trump- branded social media company to the president. The Times reported that they were involved in some of the early discussions with Mr.Orlando.

Mr. Moss and Mr. Litinksy didn't reply to questions. Mr. Moss is still employed by Trump Media.

The Securities and Exchange Commission has asked Digital World for information about the role played by the SPAC's financial adviser. Federal regulators have reprimanded the company in the past. The S.E.C. stopped the executives from listing shares of three companies due to material misstatements.

Ben Protess made a report. Beachy was involved in research.