Former Brevan Howard PM sued over $3.5m in unpaid trading profits

Quantitative researcher Wooyoung Hong is suing former Brevan Howard portfolio manager Robert Sicari for alleged non-payment of up to $3.5 million in trading profits and a 30% ownership stake in ThirtyPark Capital, a hedge fund they established in 2024, according to Bloomberg. Hong alleges that Sicari breached a compensation agreement following their departure from Brevan Howard in 2024, claiming he was promised 50% of profits from specific trades and a 30% ownership stake in exchange for developing ThirtyPark's trading infrastructure and providing quantitative research support.

The lawsuit states that Hong generated significant gains through event-driven trades tied to major corporate transactions, including Nippon Steel's acquisition of US Steel and Chevron's takeover of Hess, with trades alone yielding approximately 80% returns. Hong estimates his unpaid compensation between November 2024 and December 2025 to be $3.5 million.

He claims Sicari attempted to renegotiate their agreement in January 2025, proposing a $400,000 cash payment and a 30% profit share, but Hong rejected the terms and was subsequently denied access to ThirtyPark's trading systems. Hong, a Harvard-trained physicist and former Google employee, had a reported $400,000 base salary when he began working for ThirtyPark in 2023.

Sicari stated that ThirtyPark Capital is no longer operational but did not comment on the allegations, while his lawyer and Brevan Howard declined to comment. The case is being heard in New York State Supreme Court.