AI subject tested: Claude Sonnet 4.6 (web search on)
Question (paraphrased): A Chief Risk Officer preparing an FCM investment policy statement asked for the updated concentration limits applying to government money market funds and Treasury ETFs under the 2024 Regulation 1.25 amendments, including any size-based or tiered thresholds.
AI response:
"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"
Regulator verbatim text:
"Investments in government money market funds or qualified ETFs whose assets are ≥$1B and whose management company manages ≥$25B: may not exceed 50% of total segregated assets."
Failure mode: inference_drift
Substrate document: p_03_REGULATION_17_CFR_1_25_b__3__ii____two_tier_asset_b_download.pdf
This finding documents a confirmed hallucination by Claude Sonnet 4.6 (web search on) on a probe of the regulation. The model's response was tested against the regulator's verbatim primary text and classified as inference_drift. Full per-finding context is available via the linked Citation ID.
Each finding has a stable Citation ID (RLB-F-… for aggregated case-study findings, RLB-H-… for raw per-model hallucinations) — like a DOI, the ID always resolves to the canonical finding even if URLs change.
RegLeg Specialist Panel (2026). "A Chief Risk Officer preparing an FCM investment policy statement asked for the updated concentration limits applying to — AI Labs." Citation ID: RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Sonnet46. RegLegBrief AI Hallucination Research, published 2026-06-07. https://reglegbrief.com/regulators/j2/us/cftc/fcm-dco-customer-funds-investments-reg-1-25-2024/whitepaper/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-001--sonnet-46-websearch/
RegLeg Specialist Panel. (2026). A Chief Risk Officer preparing an FCM investment policy statement asked for the updated concentration limits applying to [Hallucination finding RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Sonnet46]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j2/us/cftc/fcm-dco-customer-funds-investments-reg-1-25-2024/whitepaper/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-001--sonnet-46-websearch/
RegLeg Specialist Panel, A Chief Risk Officer preparing an FCM investment policy statement asked for the updated concentration limits applying to [RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Sonnet46], RegLegBrief AI Hallucination Research (June 07, 2026), https://reglegbrief.com/regulators/j2/us/cftc/fcm-dco-customer-funds-investments-reg-1-25-2024/whitepaper/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-001--sonnet-46-websearch/.
@misc{reglegbrief_RLB_H_US_CFTC_FCM_DCO_CUSTOMER_FUNDS_INVESTMENTS_REG_1_25_2024_Q001_Sonnet46,
author = {RegLeg Specialist Panel},
title = {A Chief Risk Officer preparing an FCM investment policy statement asked for the updated concentration limits applying to},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-H-US-CFTC-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-Q001-Sonnet46},
url = {https://reglegbrief.com/regulators/j2/us/cftc/fcm-dco-customer-funds-investments-reg-1-25-2024/whitepaper/finding/US-CFTC-US-001-FCM-DCO-CUSTOMER-FUNDS-INVESTMENTS-REG-1-25-2024-v1-001--sonnet-46-websearch/}
}
Every finding on this page compares an AI subject's account of the rule against the regulator's verbatim text from the regulator's own portal. Both are linked. Each delta, its root causes, and impact analysis are documented and published with immutable Citation IDs.