On Thursday Devin Nunes, CEO of TMTG, wrote to Nasdaq CEO Adena Friedman claiming stocks in his company had fallen foul of “naked short-selling”—a process of traders off-loading stocks before they have either borrowed the asset or ensured it can be borrowed.

Miami-based Citadel Securities, where Griffin serves as founder and nonexecutive chairman, was named among the group allegedly engaging in this activity.

But a spokesman for the capital markets firm has resoundingly denied the allegation, saying Nunes is merely using the excuse of naked short-selling to cover up a dismal market performance.

Trump Media’s share price boomed upon its market debut in March, sitting at just over $66 a share and giving the company a market value of around $8 billion.

Yet by mid-April, this had plummeted 66% to $22, rebounding slightly to sit at approximately $36 at the time of writing.

But Citadel Securities hasn’t only dismissed the claims—it took aim directly at Nunes and branded him a “proverbial loser.”

“Nunes is exactly the type of person Donald Trump would have fired on The Apprentice,” a Citadel Securities spokesperson told Fortune.

The behemoth added that if Nunes were on its payroll it would “fire him” because “ability and integrity are at the center of everything we do.”

Trump Media was approached by Fortune for comment.

TMTG scoffs at Citadel Securities’ ‘lectures on integrity’

Not to be cowed by the damning response from Citadel Securities, TMTG hit back—alleging that the firm is “a corporate behemoth that has been fined and censured for an incredibly wide range of offenses, including issues related to naked short-selling.”

TMTG may be alluding to Citadel Securities settling charges with the SEC in 2023 over a violation of short-selling regulations. However, while the firm paid out a $7 million penalty it never admitted to, or denied, the charges.

A spokesperson for TMTG added to CNBC and the New York Post that Citadel Securities is “world famous for screwing over everyday retail investors at the behest of other corporations” and so “is the last company on earth that should lecture anyone on ‘integrity.’”

In his letter to Nasdaq, Nunes asked the index to “foster transparency and compliance,” a request it reiterated in a further filing to the SEC.

In a filing on April 19 seen by Fortune, TMTG said it wanted to explore “opportunities to collaborate with Nasdaq on matters related to short-selling.”

However, the filing took further aim at Citadel Securities, writing: “Rather than support our commonsense efforts to promote transparency and compliance, Citadel Securities bizarrely targeted our CEO with an unhinged attack.”

Griffin and Trump

While the back-and-forth between Citadel Securities and Trump Media doesn’t come down to a Griffin vs. Trump battle, it echoes the former’s resistance to back the presidential candidate.

Griffin, who owns an 85% stake in Citadel—a separate entity from Citadel Securities—giving him a net worth of $37 billion, is reportedly in the Republican’s donor class but has shied away from supporting Trump, who owns approximately 57% of TMTG stock per CNN.

In the early days of the nominee races, Griffin—who reportedly called Trump a “three-time loser,” showed interest in Ron DeSantis, the Florida governor, and then backed Nikki Haley, the former UN ambassador, with a $5 million donation, federal records show.

But as Trump has dominated the Republican field, Griffin and others said they would concentrate instead on other contests.

“I am focused on actively supporting exceptional candidates across the country, such as David McCormick, Tim Sheehy, and Larry Hogan,” Griffin said in a statement in February.

“They share my commitment to promoting economic freedom, ensuring that every child has access to a high-quality education, putting our national debt and deficit on a sustainable footing, and safeguarding our nation’s security at home and abroad.”