Claude Sonnet 4.6 maps the geometry of AI mistakes inside CFTC Reg 1.25 customer funds investment constraints.
— RLB Specialist Panel
SINGAPORE, June 10, 2026. Two frontier artificial-intelligence models generated reconstructions of the CFTC's 2024 amendments to Regulation 1.25 that drop the asset-size and management-company-size triggers governing the 50 per cent concentration ceiling, invert the carve-out set under the 24-month dollar-weighted average maturity rule, and drift on the Segregation Investment Detail Report compliance anchor, according to a white paper released today by RegLeg Brief, a regulatory-research outfit operated by Singapore-incorporated Verdus Technologies Pte. Ltd.
The findings concern the CFTC's 2024 amendments to 17 CFR 1.25, the rule governing permissible investments of customer segregated funds by registered futures commission merchants and derivatives clearing organizations, including the revised concentration limits, the portfolio-level dollar-weighted average maturity (DWAM) standard, and the separate compliance date for the Segregation Investment Detail Report (SIDR) and customer risk disclosure statement.
Both Anthropic's Claude Opus 4.7 and Claude Sonnet 4.6 were tested with web search active, mirroring how FCM chief risk officers, DCO treasury teams, customer-funds compliance officers, and regtech tools actually use the models when drafting investment policy statements, scoping segregated-fund concentration testing, or scheduling the post-amendment SIDR update cycle.
The regulator's record on the 50 per cent concentration ceiling under 17 CFR 1.25(b)(3)(ii) is unambiguous. The ceiling is not a uniform percentage applied regardless of counterparty size; it is a conditional limit that activates only when two named size triggers are simultaneously crossed. The verbatim structure reads:
"Investments in government money market funds or qualified ETFs whose assets are at least one billion dollars and whose management company manages at least twenty-five billion dollars: may not exceed 50% of total segregated assets."
The structural register matters. The regulator characterises the 50 per cent ceiling as conditional: it engages only against funds and ETFs that clear both the one-billion-dollar fund-asset threshold and the twenty-five-billion-dollar management-company threshold. An FCM that reads the rule as a uniform percentage limit will misclassify smaller funds and incumbent name-brand managers under the wrong concentration regime.
The regulator's record on the DWAM rule is similarly explicit:
Asked which concentration limits apply to government money market funds and Treasury ETFs under the 2024 amendments, including any tiered or size-based thresholds based on fund and management company asset sizes, Claude Opus 4.7 (with web search on) wrote, verbatim:
"the final rule did not adopt tiered or FCM-size-based thresholds, the percentage limits apply uniformly regardless of FCM size"
The dropped triggers. The regulator's text in 17 CFR 1.25(b)(3)(ii) keys the 50 per cent ceiling to two thresholds: the fund's own assets must be at least one billion dollars, and the management company's assets must be at least twenty-five billion dollars. Opus 4.7 surfaced the FCM-side question correctly (the rule is not keyed to FCM size) while dropping the fund-side and management-company-side triggers that actually govern when the 50 per cent ceiling engages. A Chief Risk Officer reading the output as a uniform percentage rule would size the firm's segregated-fund book against the wrong governing structure.
The inverted DWAM carve-out. Asked what dollar-weighted average maturity limit applies to an FCM's overall portfolio of customer segregated fund investments and which asset classes are excluded from the portfolio-level calculation, Opus 4.7 wrote:
"with U.S. Treasuries held under repurchase agreements excluded from the calculation"
The regulator's carve-out set under 17 CFR 1.25(b)(3)(iv) is government money market funds, Treasury ETFs, and foreign sovereign debt. U.S. Treasury repos are not on the exclusion list. The model swapped one adjacent asset class (Treasury repos) into the carve-out while dropping the actual carved-out classes; a treasury team running DWAM concentration testing on the model's output would exclude the wrong book and over-include the right ones.
The SIDR drift. Asked for the separate compliance deadline for updating Segregation Investment Detail Reports and customer risk disclosure statements, Opus 4.7 anchored the deadline at "a separate, later date (commonly described as roughly six months to a year after the effective date)". The regulator's published anchor is March 31, 2025. The model retrieved the structural distinction (SIDR has its own date separate from the general effective date) and then drifted on the specific anchor, returning a generic range where the regulator documents a date certain.
Why it failed. The RegLeg Brief Specialist Panel writes that the failure shape is characteristic of conditional-ceiling retrieval: the model surfaces one axis of the conditional structure (the FCM-size axis) correctly and then flattens the other axes (fund size, management-company size) out of the answer. The DWAM inversion has the same shape on the exclusion side, the model has enough corpus coverage to know that some asset class is carved out from the 24-month standard but not enough to retrieve the specific carved-out set, producing a plausible substitution from the adjacent asset universe.
The failure modes are classified as inference_drift against substrate documents covering 17 CFR 1.25(b)(3)(ii), 17 CFR 1.25(b)(3)(iv), and the operative section of the Commodity Exchange Act at 7 USC 6d.
Given the parallel concentration-limit brief, Sonnet 4.6 (with web search on) wrote:
"there is no size-based tier that changes the percentages based on the FCM's total assets, the limits apply uniformly: Tier 1, Per Instrument: No more than 10% of total assets held in customer segregation may be invested in any single government money market fund"
The misdirected negation. Sonnet 4.6 produced a negation of the FCM-side trigger ("no size-based tier... based on the FCM's total assets") that is technically correct on the FCM axis but is operationally misleading: it presents the question as resolved while dropping the two triggers the regulator actually applies (fund asset size and management-company asset size). A risk officer reading the answer would walk away believing the size question has been adjudicated, when the only two size triggers that matter have been omitted.
The no-standard DWAM answer. Asked whether a portfolio maturity constraint applies to direct U.S. Treasury securities held in an FCM's customer segregated account under Regulation 1.25, Sonnet 4.6 wrote:
"The 2024 amendments do not impose a new dollar-weighted average maturity (DWAM) standard or a maximum remaining-maturity cap specifically on direct U.S. Treasury obligations... No DWAM standard or individual-maturity cap found in the 2024 amendments applies to that category."
The regulator's 24-month portfolio DWAM standard applies to direct U.S. Treasury obligations by default. The carve-out set covers government money market funds, Treasury ETFs, and foreign sovereign debt, not direct Treasuries. Sonnet 4.6 returned a no-standard answer to a question the regulator answers with a standard, the most operationally consequential failure mode in the audit because it tells the user that no compliance work is required where the regulator requires it.
The failure modes are classified as inference_drift against the same substrate.
The Regulation 1.25 findings sit inside a broader failure class the RegLeg Brief Specialist Panel has been documenting across recent regulatory instruments whose operative ceilings turn on multi-axis conditional triggers, which it calls Threshold-Trigger Elision and Carve-Out Inversion, frontier models systematically dropping one or more axes of multi-condition trigger structures, inverting narrow carve-out sets by substituting superficially-similar adjacent asset classes, and drifting from date-certain compliance anchors into generic "roughly N months after" formulations that read as procedural caveats but materially misstate the deadline.
The white paper documents the pattern across the audited question set:
A futures commission merchant Chief Risk Officer, derivatives clearing organization treasury team, customer-funds compliance officer, or regtech tool automating investment policy drafting, segregated-fund concentration testing, or post-amendment SIDR scheduling on either model would carry the dropped size triggers, the inverted DWAM carve-out, the no-standard direct-Treasury answer, and the drifted SIDR anchor into the artefacts the firm produces.
Both Claude outputs shared the same surface characteristics, structured enumerations of concentration limits and tier labels, regulator-attributed phrasing on exclusion sets, and in both models' cases, confident negations on the size-trigger axis that read as adjudicative resolutions of the question. The white paper states the operational risk plainly:
"The failure is not recoverable by the user in real-time: the model's output reads as a faithful summary of the 2024 amendments, and validation would only happen if the reader already knew that the 50 per cent ceiling is keyed to the fund's own assets and to its management company's assets rather than to FCM size, that the DWAM carve-out set is government money market funds, Treasury ETFs, and foreign sovereign debt rather than U.S. Treasury repos, that the 24-month portfolio standard applies to direct U.S.
Treasury obligations by default, and that the SIDR compliance anchor is the specific date of March 31, 2025."
FCM chief risk officers, DCO treasury teams, customer-funds compliance officers, and regtech tools advising on the 2024 amendments are the population most exposed. They use AI assistants to summarise the amended rule, draft investment policy statements, and structure concentration-testing playbooks against the post-amendment compliance calendar, the exact workflow in which the failure surfaces.
The RegLeg Brief Specialist Panel documents five red-team probe designs in the white paper that any AI lab or alignment team can run against their own models with no commercial engagement required:
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RegLeg Brief is operated by Verdus Technologies Pte. Ltd. (UEN 201616982R), incorporated in Singapore. The RLB Specialist Panel, with an aggregate of over 60 years of public-policy and industry experience, documents only confirmed hallucination findings, under a methodology that requires a verbatim regulator excerpt for every documented claim. All findings, citation IDs, model outputs, regulator excerpts, and methodology notes are open-access.
Primary source verified: CFTC Amendments to Regulation 1.25, Permissible Investments of Customer Funds by Futures Commission Merchants and Derivatives Clearing Organizations (2024) · Substrate documents: R1-ACT-Q4_7_USC_6d_Commodity_Exchange_Act.pdf, p_03_REGULATION_17_CFR_1_25_b__3__ii____two_tier_asset_b_download.pdf, p_03_REGULATION_17_CFR_1_25_b__3__iv____dollar_weighted_download.pdf · eCFR: ecfr.gov · CFTC: cftc.gov
Citation IDs referenced:
RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Opus47RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Sonnet46RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q002-Opus47RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q002-Sonnet46RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q004-Opus47For AI Labs