The list the model wrote wasn't the list in Regulation 1.44.
Both frontier models fabricated regulatory structure when answering questions about CFTC Regulation 1.44. Rather than reproducing the rule's enumeration, they reconstructed lists from operational memory, producing enumerations that are plausible-sounding, internally consistent, and wrong.
📅 Published 7 Jun 2026⚙️ Methodology v2.3📋 CFTC Reg 1.44 · FCM Margin · Separate Accounts
Reg 1.44 text
Account class AAccount class BAccount class C
↓ model
Model output
Account class AAccount class B (wrong terms)Account class D (invented)Account class E (invented)
Enumeration collapse — a specific, reproducible failure mode
Enumeration collapse — definition
A failure mode in which a model, asked to reproduce or describe a specific enumerated list in a regulatory text, instead reconstructs a list from contextual or operational priors — producing items that are plausible-sounding within the regulatory domain but that do not match the actual enumeration in the source text. The reconstructed list may partially overlap with the actual list but will include invented items, wrong terms, or items from adjacent regulations.
Regulation 1.44 governs FCM margin adequacy requirements and the treatment of separate accounts. Its operative structure depends on a specific enumeration of account categories and the margin treatment applicable to each. Both Claude Opus 4.7 and Claude Sonnet 4.6, each with web search active, produced outputs that reconstructed this enumeration from operational memory rather than from the regulation text, generating lists that included invented account categories not present in Regulation 1.44.
The enumeration failure here compounds through the model's output: the model invents an account category, then derives margin treatment for that invented category from the same operational priors that produced the category itself. The resulting output is a self-consistent but factually wrong picture of the regulation, internally coherent, plausibly structured, and not verifiable against Regulation 1.44 because the category does not appear there.
Model output — reconstructed enumeration
Produced account category lists that included items not enumerated in Regulation 1.44, with margin treatment obligations derived for those invented categories. Presented as a complete description of the regulation's structure.
Regulation 1.44 — actual enumeration
Specific enumerated account categories with defined margin adequacy requirements for each. The enumeration in the regulation text is the authoritative source. Items outside that enumeration do not have regulatory status under Reg 1.44.
Enumeration collapse propagation: the model generates invented categories, then derives margin treatment for those categories from the same operational priors, producing a coherent but unfounded output.
Who is affected
FCM compliance teams and margin operations
CFTC Regulation 1.44 is directly relevant to FCM compliance officers, margin operations teams, external auditors reviewing FCM books, and legal counsel advising on separate account treatment. When an FCM uses an AI tool to research the account categories and margin adequacy requirements under Regulation 1.44, an enumeration collapse error produces a compliance picture built on categories the regulation does not recognise.