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Claim No: IL-2025-000064 - [2025] EWHC 2545 (Ch)
Fecha: 06-Oct-2025
Heading
IN THE HIGH COURT OF JUSTICE
BUSINESS AND PROPERTY COURTS
OF ENGLAND AND WALES
INTELLECTUAL PROPERTY LIST (ChD)
Rolls Building
7 Rolls Building,
Fetter Lane
London EC4A 1NL
Tuesday, 6 October 2025
Before
HIS HONOUR JUDGE HODGE KC
Sitting as a Judge of the High Court
BETWEEN:
(1) Braunford LLP
(2) Corbiere Limited
(a company incorporated under the laws of the Marshall Islands)
Claimants
-v-
Pierre Allain
Defendant
_______________________________
Mr DAVID CRAIG KC, Mr CHARLES CIUMEI KC, Mr ALEX RIDDIFORD, and Mr CHRISTIAN DAVIES (instructed by Allen Overy Shearman Sterling LLP) appeared on behalf of the Claimants
Ms KENDYA GOODMAN (instructed by Rakasons Limited)appeared on behalf of the Defendant
This Transcript is Crown Copyright. It may not be reproduced in whole or in part other than in accordance with relevant licence or with the express consent of the Authority. All rights are reserved.
EMPLOYMENT – Confidential information – Issues for disclosure – Whether defendant to have permission to call expert evidence of quantitative or algorithmic trading strategies – Principles governing the grant of permission for expert evidence – Relevance of confidentiality restrictions imposed during the course of the litigation to protect the claimant’s interests on the admission of expert evidence to resolve disputed issues of fact – Relevance of the burden of proof on the admission of expert evidence
The following case law authorities are referred to in this judgment:
AlphaSharp Ltd v ADG Capital Management LLP [2021] EWHC 1779 (Comm)
Astex Therapeutics Ltd v AstraZeneca AB [2017] EWHC 1442 (Ch)
Barings Plc v Coopers & Lybrand [2001] PNLR 379
Bridgewater Associates LP v Minicone 16 July 2020 (Employment Arbitration Tribunal)
British Airways v Spencer [2015] EWHC 2477 (Ch)
CF Partners (UK) LLP v Barclays Bank Plc [2014] EWHC 3049 (Ch)
Clifford v Chief Constable of the Hertfordshire Constabulary [2008] EWHC 2549 (QB)
Henderson & Jones Ltd v Salica Investments Ltd [2025] EWHC 475 (Comm)
Lombard North Central Plc v Airbus Helicopters SAS [2020] EWHC 3819 (Comm)
McParland & Partners Ltd v Whitehead [2020] EWHC 298 (Ch), [2020] Bus LR 699
Performing Right Society Ltd v Qatar Airways Group QCSC [2021] EWHC 869 (Ch)
The RBS Rights Issue Litigation [2015] EWHC 3433 (Ch)
Stellantis Auto SAS v Autoliv AB [2024] EWCA Civ 609, [2024] 1 WLR 4728
APPROVED JUDGMENT
This judgment was handed down remotely at 10.30 am on Tuesday 7 October 2025 by uploading it to CE-File, by circulation to the parties’ legal representatives by e-mail, and by release to the National Archives.
HIS HONOUR JUDGE HODGE KC:
Introduction
- Heading
- Introduction
- Background
- Case management issues
- Disclosure: legal principles
- The first three of these propositions may be distilled from McParland , the fourth from Lombard North Central , and the fifth from PRS v Qatar Airways Group
- Multiple, and overlapping, issues for disclosure should be avoided wherever possible
- Disclosure: Submissions, analysis and conclusions
- I have not yet decided whether this should form one of the issues for disclosure. But if it were to do so, then it would seem to me to eliminate all need for disclosure issue 4 since it makes it unnec
- To the claimants’ knowledge, the defendant could not have replicated Humber elsewhere. Accordingly, the claimants’ case with respect to any Springboard relief (insofar as it is based on the possibilit
- The defendant cannot see that this possibility has been considered by the claimants. The defendant is therefore concerned about the nature of any searches the claimants will have undertaken concerning
- Further, I consider that the claimants place too much emphasis upon the defendant’s own repeated assertions, in contemporaneous documents, that he could (and would) ‘replicate’ Humber (as reproduced a
- Expert evidence: legal principles
- The burden of establishing that expert evidence is both (i) admissible and (ii) reasonably required (in the sense that it is not just ‘potentially useful’ ) is on the party which seeks permission to a
- Barings is authority for propositions (1) and (2); Clifford for proposition (3); The RBS Rights Issue Litigation for proposition (4); British Airways for propositions (5) to (9); and Astex for proposi
- At p. 11, the tribunal described the respondents’ experts’ evidence as “ independent, impressively detailed and completely credible ,” and further that
- Ms Goodman submits that this arbitral decision demonstrates the utility of an expert in this type of assessment as lawyers are obviously ill-equipped to know, and the court will be ill-equipped to adj
- In Henderson & Jones Ltd v Salica Investments Ltd [2025] EWHC 475 (Comm) , Calver J (at paragraph 236) is said to have ordered expert evidence to assist in determining “ (i) whether the allegedly conf
- The decision tells the court nothing about whether or not expert evidence should be ordered in a case governed by the Civil Procedure Rules. That case involved an arbitration. Mr Craig KC rightly says
- Practical utility of confidential information The defendant proposes to rely on the expert evidence of Mr Colin Knight, a qualified trader with over 20 years’ experience in trading strategies. Ms Goodman points out that algorithmic trading was ac
- The claimants have themselves relied on the expert report of Mr Winrow to analyse the coding data extracted from the defendant’s electronic devices, as evidenced by A & O Shearman’s letter of 5 Septem
- It is the claimants who bear the burden of proof in this case, which concerns the nature, and value, of technical descriptions of algorithmic trading strategies and actual code. They are required to p
- Stage in trading strategy development – identifying which stage in the trading strategy development process each piece of ‘confidential information’ (as defined in the particulars of claim) pertained
- The assertion that there are a certain number of stages in the development of a trading strategy at G-Research is the defendant’s own construct , in the sense that it is not said to be a framework ref
- Public domain assessment – assessing whether the ‘confidential information’ was, as a matter of fact, generic and/or widespread industry knowledge within the field of quantitative investment, such tha
- The claimants emphasise that the defendant well knows that the information in issue in this case is not generic and/or widespread industry knowledge. That is precisely why he admits to saying (in an u
- Valuation of confidential information – determining the value of the ‘confidential information’ to a competitor, including with reference to various dates The claimants’ case is that the defendant well knows that Humber is highly valuable: see the co
- Retention of value – Assessing whether, and to what extent, the ‘confidential information’ is likely to retain its value over time, including over a one-year period of garden leave Quite apart from the disproportionate nature of the exercise (not lea
- Practical utility of confidential information – Assessing whether, and to what extent, other businesses (including Citadel Securities) could utilise the ‘confidential information’ in their business ac
- If material at all, this is a question of fact; but, in any event it is extremely difficult to understand how an expert would be able to opine on this matter: it suggests that there would be some reco
- Stage in trading strategy development The claimants submit that the assertion that there are a " number of stages in the development of a trading strategy " is a mere construct. The defendant contends that there is a logical difference be
- Public domain assessment
- The defendant submits that, at most, he referred to Humber at the highest degree of generality, and that the summary to which the court was referred was of minimal value. The parties are, accordingly
- Valuation of confidential information At paragraph 3 of their particulars of claim, the claimants plead that the claim " concerns the defendant's misuse and copying of the claimants' extremely valuable and sensitive confidential informati
- Retention of value Even if the defendant had the requisite knowledge and ability to ‘replicate’ Humber, establishing when Humber is likely to lose its value (through the process of alpha decay) will be the primary consi
- Practical utility of confidential information Conclusions