Claim No: IL-2025-000064 - [2025] EWHC 2545 (Ch)

The essence of the final issue is a very simple question. The expert is invited, using his or her algorithmic trading experience and industry knowledge, to consider a simple question: if the defendant had come to you with the GR Information, could you have meaningfully used it? That is to say: if the defendant's case is right, and his assertions that he could ‘replicate’ Humber (for example) were mere hot air (in that he could not do so himself), could another team have done so, based on the information which he misappropriated? This issue is central to the defendant's contentions, both that the code was ‘upstream’, but also that a competitor would not be able to progress the ‘upstream’ information to which the defendant had access into ‘downstream’ alpha, or implementing, code (as pleaded at paragraph 38.5 of the defence). If a third party could not have created a valuable trading strategy off the back of what the defendant misappropriated (which includes the description of Humber at paragraph 15 of the claimants' confidential schedule), then the claimants' entitlement to relief will be severely constrained. As with the other issues, this is apposite for determination by a single joint expert because, whilst it is controversial as between the parties, a single comprehensive answer to this issue would assist in putting it to bed.

I do not consider that expert evidence on this topic is necessary for the court to be able to determine any of the issues arising in these proceedings or the proceedings as a whole. Nor do I consider that such evidence would be of any real assistance to the court. I do not agree with Ms Goodman that it is either necessary, or helpful, for the trial judge to know the stage in the development of the claimants’ algorithmic trading strategy to which the information the defendant copied relates. I agree with the claimants that, to whatever stage such information relates, the real question for the court is whether, as a matter of fact, that information possesses the attributes and quality of a trade secret which the claimants are entitled to protect by way of far-reaching injunctive relief. That falls to be determined on the factual evidence adduced at trial. In my judgment, that issue is one on which the court is able to come to a fully informed decision without hearing the evidence of an expert in quantitative trading.

I agree with the claimants that the question whether,as a matter of fact, the confidential information captured by the defendant was generic, or widespread, industry knowledge within the field of quantitative investment, so as to be considered as being in the ‘public domain’, is a question of fact to be determined on the evidence that is adduced before the court. It is not properly a matter for expert evidence. It is no doubt in recognition of this point, that Ms Goodman has recently sought to re-characterise this topic as the ‘industry knowledge assessment’. But it seems to me that she has also sought to refine the topic for the expert:

I do not consider that expert evidence on this issue is either necessary or reasonably required to enable the court to determine any of the issues in this litigation, or the proceedings as a whole. The information captured by the defendant cannot be treated as confidential if it is common knowledge, or generally accessible and in the public (or industry) domain. Whether this information is common knowledge, or generally accessible, amongst those engaging in the trading of financial products is a question of fact, to be determined on the factual evidence adduced at trial, rather than a matter for expert opinion evidence. I bear in mind that it is the claimants who bear the burden of proof in this case; and it will be open to the defendant to submit that the lack of any expert evidence in support of their case militates against the discharge of this burden.

I can take these two proposed expert evidence issues together since they seem to me to give rise to similar considerations. They both raise issues of fact on which the court will be well able to come to a fully informed decision without hearing the evidence of an expert. As Mr Craig KC has demonstrated, by reference to authority, a claimant does not need to establish financial value to maintain a claim for breach of confidence or copyright. Information can have commercial value simply because it is secret. There is inherent value, effectively, in the secrecy, and the inaccessibility, of confidential information. The primary relief sought by the claimants is injunctive, rather than an award of damages. To the extent that they do seek to recover damages, this can be the subject of an inquiry before a Master after the conclusion of the trial in the usual way. I do not consider that expert evidence on the issues of the value of the information, or its retention, is either necessary, or reasonably required, to enable the court to determine any of the issues in this litigation, or the proceedings as a whole. Once again, I bear in mind that it is the claimants who bear the burden of proof in this case; and the defendant can point to the absence of any expert evidence in support of the claimants’ case in support of any submission that they have not discharged this burden.

In his witness statement, Mr Sheikh states that expert evidence on this topic will involve “assessing whether, and to what extent, other businesses (including Citadel Securities) could utilise the confidential information in their business activities”. Like Mr Craig KC, I am not satisfied that this is a helpful way of describing the nature of the expert evidence required on this topic. How is Mr Knight to be expected to assess the practical utility of the claimants’ confidential information to other businesses (including Citadel Securities) when, of its very nature, he is unlikely to have access to their existing confidential information? It seems to me that the same objection would apply to the simple question posed by Ms Goodman: “if the defendant had come to you with the GR Information, could you have meaningfully used it?” However, without trespassing outside the bounds of the topic identified by Mr Sheikh, it seems to me that the exercise envisaged by this issue could usefully be reformulated as follows: Whether the confidential information copied by the defendant would assist a hypothetical competitor of the claimants in developing, or duplicating, a trading strategy; and, if so, in what circumstances, to what extent, and for how long? I do not consider that such expert evidence is absolutely necessary for the court to be able to determine any of the issues in these proceedings, or the proceedings as a whole. If it were, then the absence of any expert evidence on this issue would clearly weigh strongly against the claimants’ case. But I do consider that such evidence would be of real, and material, assistance to the court when it comes to determine the nature, and the duration, of any injunctive relief to be granted to the claimants. In this sense, I consider that such evidence is reasonably required to resolve an issue in these proceedings. I doubt whether the judge trying this case will have any previous experience, whether professional or forensic, of quantitative trading strategies. I acknowledge Mr Craig KC’s objection that the defendant will be entitled to assert before the trial judge that the claimants’ confidential information would be of no interest or use to any other business; and that the trial judge will be able to take a view about that, bearing fully in mind what the defendant was saying about the utility of the information he possessed at the time. But, inevitably, Mr Craig KC’s submissions are advanced through the lens of the claimants’ own case, and pay little attention to the terms, and nature, of the pleaded defence. In my judgment, equality of arms requires that the defendant should be permitted to rely upon expert evidence on this issue. Further, issues of proportionality, timing, and costs, particularly in the context of an expedited trial, indicate that such evidence should be given by a single joint expert, albeit subject to written questioning on their expert report. As Ms Goodman rightly submits, if a third party could not have created a valuable trading strategy off the back of what the defendant misappropriated, then the claimants' entitlement to relief will be severely constrained. In my judgment, the claimants’ competing submissions do not engage with this point. I agree with Ms Goodman that this issue is appropriate for determination by a single joint expert because, whilst it is controversial as between the parties, a single comprehensive answer to this issue may assist in putting the issue to bed.

Conclusion