The High Court's judgment following the second Case Management Conference ("CMC") in California State Teachers' Retirement System v Boohoo Group plc [2026] EWHC 1944 (Comm) ("Boohoo") provides guidance on the Court's approach to issues of reliance in claims brought under s.90A/Schedule 10A FSMA 2000.

Background:

The second CMC ("CMC2") in Boohoo took place on 14 July 2026 following Mr Justice Green's prior decision that reliance should be determined as part of trial 1 (see our earlier blog post here). CMC2 focused on three main issues in relation to the process for determining the question of reliance:

1. Sample claimants: striking the right balance

Boohoo accepted the claimants' proposal of six sample claimants but sought the addition of a further five sample claimants who had indicated that a relevant individual had read the published information. Boohoo's position was that including this entire category of claimants in the sample was necessary as it was otherwise unclear whether all the published information was included. Boohoo was concerned that, if this category of claimants were not included, then non-sample claimants, who had not yet provided their particulars of reliance, could wait for the findings in trial 1 and then tailor their case on reliance accordingly.

While acknowledging Boohoo's concerns, Green J rejected its proposal to include this entire category of claimants in the sample. In his view, including all claimants from one category "defeats the purpose of sampling" [16] because sampling is intended to provide broad coverage from a limited pool of claimants, rather than include every claimant within the same category.

Green J permitted the addition of two further sample claimants which were chosen by Boohoo on the basis that they had the highest value claims.

Green J noted that it would be important that "in due course the defendant does know which bits of published information are relied on by each claimant" [19]. His observation underscores the need for particularisation of each claimant's case on reliance.

2. Expert evidence: real evidence over assumptions

The claimants sought permission to adduce both corporate broking evidence and econometric evidence directed at market price reliance at trial 1. Boohoo was neutral in relation to the corporate broking expert but opposed the admission of econometric evidence. Boohoo argued that the Court could instead proceed on the assumption that the market was efficient or, alternatively, that at least some of the published information would, at some point in the relevant period, have influenced the share price. Boohoo offered to proceed on this assumption for trial 1, on the basis that it would not be bound by it in any future trial 2, including in respect of the issues of causation. The claimants were not willing to proceed on that basis and sought an admission from Boohoo that the published information did impact the share price, which Boohoo was not prepared to give.

Green J granted permission to admit both categories of expert evidence. In relation to common reliance, he stated that one of the critical issues is whether Boohoo's share price was influenced by other market participants who had read or taken into account the published information. He observed that markets may have different degrees of efficiency. Where there is strong efficiency, all public information is necessarily taken into account, but there are also less efficient markets where only some of the information is taken into account, and so the information can be less influential. An expert could therefore assist the Court in determining the degree of efficiency in the market for Boohoo shares.

The Court also rejected Boohoo's argument that these issues would be more appropriately dealt with in trial 2 in the context of causation. Although Green J acknowledged the overlap between reliance and causation, he emphasised that, because reliance falls to be determined at trial 1, all issues relevant to common reliance are live.

3. Disclosure: a proportionate approach to reliance evidence

Boohoo also sought disclosure of documents referred to in the claimants' reliance questionnaires, arguing that this material would assist it in formulating its disclosure proposals and understanding the claimants' reliance cases. The claimants resisted the application, noting that full disclosure was due in October 2026 and arguing, therefore, that the request was premature.

Green J declined to order this disclosure. Given the proximity of standard disclosure, he considered there was little practical benefit in requiring the documents to be produced early.

Key takeaways:

1. Representative sampling not exhaustive inclusion: When selecting sample claimants, parties should focus on including a broad range of claimants, rather than including every claimant within any particular category.

2. Particularisation of individual reliance cases: As the proceedings progress, claimants will be required to particularise their reliance case, including by identifying the specific pieces of published information on which they claim to have relied.

3. Expert evidence on market price reliance: Courts may be reluctant to determine the complex question of market price reliance and the resulting legal issues that arise based on assumptions when expert evidence may assist in assessing the extent to which the alleged misleading information affected a company's share price.