Trump Media & Technology Group “was founded with a mission to give a voice to all,” Mr. Trump said in the release.

Also called a blank-check firm, a SPAC is a shell company that lists on a stock exchange with the sole intent of merging with a private firm to take it public. The private company then gets the SPAC’s place in the stock market. SPAC mergers have exploded in popularity in the past year for many startups because they are allowed to make projections about their business. Those aren’t allowed in normal IPOs.

The Digital World Acquisition SPAC has about $290 million on hand. Mr. Trump’s firm could use the money held by the SPAC to fund its growth, but that cash pile could shrink. That is because SPAC investors have a right to pull their money out of the deal before it is completed. Such withdrawals have skyrocketed in recent months, with shares of many SPACs falling after some companies that went public this way struggled to meet their growth targets.

Asked whether the deal would include private investment in public equity, or PIPE, financing, which often accompanies such deals, a spokesman for the SPAC said it couldn’t provide more details but would reveal more publicly soon.

Several former Trump administration officials are involved with their own SPACs, including

Wilbur Ross,

Larry Kudlow

and

Gary Cohn.

SPAC deals have become a hot fundraising tool for digital-media startups. BuzzFeed Inc. announced a roughly $1.5 billion SPAC merger in June.

Write to Amrith Ramkumar at amrith.ramkumar@wsj.com