The share price of plunged more than 10% on Wednesday, a day after majority shareholder gave a widely panned presidential performance against Vice President .
The company's stock price closed at its lowest level since the app owner began publicly trading as on the in late March.
Investing in Trump Media stock is often seen as a way to bet on the political fortunes of Trump, the former president and current Republican nominee.
Trump Media has said its business hinges at least partly on Trump's popularity, and analysts say the company's value will rise or fall based on his electoral prospects.
The stock drop Wednesday could signal that some Trump's supporters were not pleased with what they saw at Tuesday night's debate in Philadelphia.
Liberal and political commentators said Harris appeared more prepared, articulate and even-keeled than Trump, who repeatedly bit on bait that she tossed to throw him off topic.
Harris' team, projecting confidence, challenged Trump to another debate right after the first one ended.
Trump said he may not agree to that. In a Wednesday, he repeated his claim that Harris only wanted another debate because she was "beaten badly."
"Why would I do a Rematch?" he wrote in the post.
Trump Media had surged as much as 10% during trading Tuesday, possibly indicating optimism about how Trump would fare in the debate.
The company's gains on Monday and Tuesday were a respite from a weekslong rout that saw the stock price sink as much as 75% from its intraday high in late March, when then-privately held Trump Media merged with a blank-check firm.
The slump coincided with President dropping out of the presidential race and endorsing Harris to replace him at the top of the Democratic ticket.
It also came in the run-up to the date when Trump and other company insiders can start selling their shares.
Trump owns nearly 57% of the company's stock. That stake at Wednesday's closing price was worth about $1.9 billion.
It is unclear if Trump plans to start selling off his stake when a lock-up agreement lifts on Sept. 19.
Correction: Donald Trump owns nearly 57% of Trump Media's stock. An earlier version misstated the percentage.
