Two rival quant funds traded accusations of poaching, harassment and dishonesty at the start of an acrimonious London trial over a “highly paid” star trader and confidential trading information.

Jump Trading Group accused its ex-employee, Damien Couture, of dishonesty and misleading the firm by working for Verition Fund Management while he was on gardening leave. Jump asked a judge at the High Court to enforce a two year non-compete clause on Couture, including 12-months before he can work again, to “protect its business from any future similar attack,” its lawyers argued.

Jump “is using a claim in breach of confidence to harass a perceived competitor and an ex-employee,” Adam Solomon, Verition’s lawyer, said in documents prepared for the 10-day trial that started this week. “The claim is hopelessly vague.”

The lawsuit reflects the fierce competition between high-frequency traders and the clamor for talent in algorithmic trading where firms go to extreme lengths to protect closely guarded secrets. The UK’s courts have often hosted funds and traders quarreling over trading strategies. The government plans to prohibit firms from imposing a non-compete clause of more than three months to encourage productivity.

Couture, who joined Verition in May after Jump failed twice to stop him from starting at the rival firm, disputes the allegations. It would be impossible to remember millions of lines of secret code and formulae and “two years is an inordinately long period for a non-compete clause,” his lawyer Niran De Silva said.

The details from the hearing reveal a 2015 offer by Jump to hire Couture with a package that included £1 million ($1.2 million) in guaranteed pay in the first year of employment. Jump sought a court order to recover over $500,000 paid to Couture in January 2022 as a discretionary bonus.

Lawyers for Couture, who specializes in quantitative analysis for trade strategies, said it was “fanciful” of Jump to suggest he could work in machine learning or academia. “His expertise is in finance, his degree is in finance and finance is the industry where he has spent the last 15 years.”

Jump’s trading methodologies are highly confidential information that forms the “lifeblood” of the business, Jump’s lawyer James Laddie said.

Couture knew Verition was “desperate to hire him,” Laddie said. The fund was “keen to show their love” for him.

Jump’s claim is designed to keep Verition embroiled in proceedings “in order to exert commercial pressure and cause maximum inconvenience, rather than to pursue a remedy of any real value,” Verition’s lawyer said.

Spokesperson for Jump and a lawyer for Couture declined to comment. Verition’s spokesperson didn’t respond to an email seeking comment.

(Updates with details from court documents in the sixth and seventh paragraphs.)