The compromising iPad photos that dragged a London quant trader to court
An additional point of context was added to the end of this article on 23 June 2026.
It’s never easy moving jobs in the Square Mile – especially for the higher ups. Once you reach a certain seniority, your employer frets over the threat posed if you jump ship – what strategic information you could take with you.
That was true for a London-based quant firm called G-Research, after one of its employees, Pierre Allain, handed in his notice.
When Allain quit in March, G-Research put him on 12-months’ paid garden leave, such were their concerns over his knowledge of their secret trading strategies. What happened next is very much in dispute and Allain emphatically denies any wrongdoing.
Allain had been offered his dream job, to be a quant trader at the mighty Citadel – with a hefty pay rise to boot (or not, depending on who you ask – on which more later).
As a welcome gift, Citadel sent Allain an iPad – a lovely thought. But what he did with it took bosses by surprise.
G-Research’s suspicions first arose in the days following Allain’s resignation. System logs uncovered that he had spent several hours the weekend prior to his resignation remotely accessing his work computer, according to court filings.
Perhaps Pierre was simply a devoted, fastidious employee, who wanted to get a few bits of work tied up before he hung up his hat? Not so, says G-Research.
The company alleges the French national accessed various parts of its systems he did not usually access – including attempts to access top-secret folders he did not have permission to access – in order to build up a picture (or “exfiltrate a schematic”) of its trading strategies.
How did he save the data? By taking pictures of his laptop screen, using the new iPad. And Allain built up quite the album. Over the course of a few hours, the departing employee took over 1,000 photos of confidential company information.
At least 400 of the photos relate to a secret project called Humber, which sets out G-Research’s highly lucrative trading strategy.
G-Research alleges Allain “unlawfully copied the [firm’s] confidential information and trade secrets in order to misuse that information for the benefit of his career.”
How did the company arrive at this dramatic conclusion? Before taking the pictures, Pierre helpfully created a file on his laptop called “summary”, containing notes he made to prepare for job interviews, in which he describes an overview of Humber, and claims: “I could replicate this alpha easily.”
“I know I can make an impact from day one – whether by replicating and refining successful approaches…” Allain wrote.
G-Research phoned up the lawyers, and the company is now seeking a three-year ban on Allain working for a rival, as well as extensive damages for breach of contract.
For his part, Pierre Allain admits taking the iPad photos and making the notes – but “contends that they were nonetheless not of trade secret quality, and that some of the information was in the public domain and so not confidential at all.” He applied – unsuccessfully – for an anonymity order. The trial has yet to begin.
There are reasons Mr Allain might be worried. G-Research has more than enough spare cash to throw at this case – and this is not the first time it has pursued a former employee.
Back in 2018, another ex-staffer, Ke Xu, abruptly quit his job and moved back to his native China, after spending a surprising amount of time on his work computer. G-Research suspected he had stolen intellectual property and sent lawyers Allen & Overy after him. He would later be sentenced to four years in prison. In Allain’s case, though, it is not suggested that he has done anything criminal.
The mysterious world of the quants
The legal battle underscores the highly secretive nature of quantitative trading, a mysterious industry in which maths geniuses use highly sophisticated models to automate trading in financial markets. Get it right and firms can make – and pay their staff – eye-watering sums of money.
London’s best-known quant trading firm, XTX, made £1.3bn in profit earlier this year, with its billionaire founder, the outspoken Alex Gerko, pocketing £682m alone. The remaining £597m was shared between just 30 traders. Another firm, Quadrature Capital, recently turned a profit of £411m. Last year it made the biggest-ever donation to the Labour party.
G-Research is part of a firm called Corbiere, which is incorporated in the Marshall Islands, a place famed for its expertise in quant trading – and which also happens to have very low taxes and a light-touch regulatory regime.
The territory’s opaque corporate disclosures makes it hard to know quite how much money G-Research is making, but at least one entity within its corporate structure, called Island Research, turned over £620m in 2023, while another, called Trenchant, made £92m.
G-Research was set up by British financier Peter de Putron, a Cayman-based old Etonian, and is run by Ben Leadsom, husband of erstwhile prime ministerial contender, Andrea Leadsom.
The company has once again hired A&O Shearman to fight the case – a firm whose partners typically charge upwards of £1,000 an hour. Not a trivial sum to spend over some indiscreet iPad photos.
Mr Allain, on the other hand, is an “individual of limited means”, court documents say.
His lawyers are a little less well known – and they did not respond to a request for comment. That did not come as a huge surprise, as the law firm has yet to get round to setting up a website.
Surely, as an ex-quant firm employee, Allain was making pretty tasty money? Citadel certainly thought so.
According to court filings, in job interviews he told the US firm he had been on a base pay of £180,000 in 2023, rising to 200,000 in 2024, and set to rise to £230,000 in 2025.
But G-Research says the Frenchman was actually paid £125,000 in 2023, £125,000 in 2024 and, er, £125,000 in 2025. Sacrebleu.
If Allain loses, he could be on the hook for G-Research’s legal costs, unlikely a small sum. And in light of the legal imbroglio, will he get to keep his new job?
“Citadel Securities said it rescinded Mr. Allain’s offer upon learning of these actions,” the company told me in a statement.
I hope he keeps the iPad.
Update June 2026: The proceedings between G-Research and Pierre Allain were subsequently settled on confidential terms before trial without judicial determination of the disputed allegations.