What the AT1 Cases Reveal Under Stress
The BIS procedure becomes more persuasive when its ranked candidates are tested against instruments whose wording later mattered. This chapter reads the large-scale AT1 exercise as a description of where the queue directs attention, then reconstructs the Credit Suisse and Yes Bank validations without turning either into a claim that the model resolved a legal dispute. The useful judgment is narrower: whether early comparison can expose contractual differences before stress or regulatory change makes them expensive to interpret.
The scale exercise shows where a queue points
The BIS applied its procedure to AT1 instruments issued by 10 European global systemically important banks, or G-SIBs. The sample covered six banks in the European Union, three in the United Kingdom, and one in Switzerland. Each prospectus was compared with the capital rules applicable in its regulatory regime: the EU Capital Requirements Regulation together with the Bank Recovery and Resolution Directive, the UK Prudential Regulation Authority Rulebook, or the Swiss Capital Adequacy Ordinance.
The point of this exercise was not to produce a league table of compliant and non-compliant banks. It was to see which parts of the contractual design repeatedly attracted comparison candidates across a meaningful set of instruments and jurisdictions. That distinction matters because the sample is not balanced across regimes, and the number of institutions in each jurisdiction differs. The resulting counts describe the composition of the queue, not the prevalence of divergence in one legal system compared with another.
The candidates clustered around the terms that determine when and how loss absorption begins. Mechanical triggers and point-of-non-viability, or PONV, provisions accounted for roughly two thirds of the retained high-recurrence candidates. That concentration is intelligible. These terms determine whether a capital threshold has been crossed or whether an authority can require a write-down or conversion. A wording difference in either place can affect the moment at which losses move from a bank’s balance sheet to an instrument’s holders.
The other AT1 features remain relevant. Coupon terms govern when payments can be cancelled without default, which affects capital conservation before a full loss-absorption event. Hierarchy determines whether common equity or AT1 bears losses first, which affects how different classes of investors share the burden. The queue’s concentration on triggers and PONV does not mean coupons and hierarchy are unimportant. It means that, in this exercise, the repeatedly returned candidates were more concentrated in the provisions governing the start of loss absorption.
The mix of divergence types also differed across jurisdictions. Narrowings were most common in Switzerland, expansions in the United Kingdom, and omissions in the European Union. Those observations can help a supervisor decide where to inspect the wording and what kind of question to ask. A Swiss candidate may invite attention to an added contractual qualification; a UK candidate may prompt examination of language that extends a requirement; an EU candidate may direct the reviewer to a missing condition or procedural step.
They cannot, without more evidence, support the stronger claim that one jurisdiction’s banks diverge more often or comply less faithfully than another’s. The denominator is the set of flagged candidates produced by this exercise, not the set of all applicable provisions, all prospectuses, or all banks in each regime.