Trump Media & Technology Group stock climbed 9% on Thursday afternoon after CEO Devin Nunes made another call to Congress to investigate firms for what he called “potential manipulation” of the company’s stock

In a follow-up letter addressed to the chairs of several House committees dated Wednesday, Nunes said the company had “identified ongoing anomalies in DJT trading,” and called on Congress to request documents and testimony from eight new firms involved in facilitating short sales: ApexClearing, Clear Street, Cobra Trading, Cowen and Company, Curvature Securities, StoneXSecurities, TradePro, and Velocity Clearing.

Nunes pointed to Trump Media’s appearance on the Nasdaq’s “Reg SHO threshold list” — a list of securities whose transactions failed to clear at a registered clearing agency for five consecutive days — since April 2 as “indicative of unlawful trading activity” of its stock.

Late last month, Nunes called on Congress to carry out a “thorough and expeditious investigation” into what the company claimed was “unlawful manipulation” of its stock through a practice known as “naked” short-selling — or the illegal sale of shares without borrowing them first.

While “naked” short-selling is a potential reason why a security would fail to clear, there are many reasons why a stock could be on the Reg SHO list.

Based on data Nunes said was made available to the company, he said just four market participants are responsible for more than 60% of the trading volume of Trump Media shares: Citadel Securities, VIRTUAmericas, G1 Execution Services, and Jane Street Capital.

Nunes had previously penned a similar letter to Nasdaq CEO Adena Friedman. In response to the letter, a Citadel spokesperson said Nunes “is the proverbial loser who tries to blame ‘naked short selling’ for his falling stock price.”

Trump Media, the company behind former President Donald Trump’s Truth Social, went public on the Nasdaq under the ticker DJT on March 26, after completing its merger with Digital World Acquisition Corp., a special purpose acquisition company, or SPAC.

It has been on a roller-coaster ride since then: Trump Media’s market capitalization has soared to highs of almost $10 billion and sunk to lows of less than $4 billion. As of Thursday afternoon, the company’s shares traded at $49.34 each, bringing its market cap to $6.74 billion.