An Employee Left Citadel Securities for a Startup. Now, He’s Facing a Lawsuit.

Vincent Prieur faces a non-compete lawsuit after joining Portofino Technologies, a crypto trading platform.

Illustration by II

Illustration by II

Less than two weeks after digital asset trading platform Portofino Technologies announced its launch, Citadel Securities has filed a lawsuit against one of the firm’s newest employees.

Vincent Prieur, who worked for Citadel Securities for three years before joining the cryptocurrency firm, is facing a lawsuit alleging that he broke his Citadel Securities noncompete agreement.

The lawsuit, filed on Friday, alleges that Prieur played a key role in developing Citadel Securities’ crypto trading platform. By joining a “key competitor that was deceptively and surreptitiously formed by other former Citadel Securities executives,” Prieur is violating his noncompete, according to the lawsuit.

The lawsuit claims that Citadel Securities will suffer “irreparable harm” if he is not barred from moving forward with this role. Prieur’s lawyers did not immediately return an email seeking comment on Monday.

“Mr. Prieur had access to confidential information as a key member of the team planning our entry into digital assets,” a spokesperson for Citadel Securities said via email. “When he left the firm Mr. Prieur agreed not to compete with us for 15 months given this access to confidential information, and we agreed to pay him during this period. He has now violated this agreement and we will fully enforce our right to protect our intellectual property.”

Portofino was founded by two former Citadel Securities leaders Leonard Lancia and Alex Casimo in 2021. On September 15, Portofino announced its official launch, and that it had raised $50 million in equity funding from Valar Ventures, Global Founders Capital, and Coatue.


The announcement, which includes Lancia and Casimo’s backgrounds at Citadel Securities, said Portofino provides liquidity for large cryptocurrency exchanges, as well as services for institutions and Web3 projects seeking digital asset liquidity.

Citadel Securities is in a separate legal battle with Lancia and Casimo, according to its lawsuit against Prieur.

When he worked for Citadel Securities, Prieur served as senior vice president in the office of the chief operating officer. He was part of a team that researched and developed a strategy for the firm to enter the cryptocurrency market, helping to coordinate internal staff changes and external recruiting for the business line, in addition to sharing research among team members, according to the lawsuit. “Prieur was intimately involved over the course of several months in the research and development of Citadel Securities’ entire highly confidential crypto trading and market-making strategy,” lawyers for Citadel Securities wrote.

In March 2022, Citadel Securities, through an affiliate, executed its first systematic crypto trade. Four days later, Prieur resigned.

According to the lawsuit, Prieur was subject to a 15-month non-compete period, under which the company would provide a monthly payout of $15,000 to $18,000 if he complied with the agreement.

On September 9, Prieur informed Citadel Securities that he began the new role at Portofino. According to the lawsuit, under the terms of the non-compete, Prieur was required to provide the firm with 14 days’ notice before becoming employed. This, in addition to the firm’s belief that Portofino is a direct competitor, is allegedly a violation of the non-compete agreement.