AI subject tested: Claude Sonnet 4.6 (web search on)
Question (paraphrased): A financial economist preparing testimony for a Congressional briefing on regulatory inflation adjustment has asked you to draft a brief technical note quantifying the inflation gap that the CFTC's September 2024 amendments to Regulation 4.7 sought to address. The note should give the specific CPI-U-based buying-power calculations the CFTC documents in the NPRM and the final rule, with citations to the relevant Federal Register passages.
AI response:
"The October 2023 NPRM used CPI-U data through approximately February 2023 to document the inflation gap at the time of the proposal. At that reference month: $2,000,000 in 1992 dollars approximately equals $4,070,000 in February 2023 dollars (approximately 103.5% cumulative inflation); $200,000 in 1992 dollars approximately equals $407,000 in February 2023 dollars."
Regulator verbatim text:
"NPRM pre-print PDF (R4-FINAL_RULE-00021, Wayback-rescued from cftc.gov media URL): 'using CPI-U data, as of February 2023, the $2,000,000 threshold in the Securities Portfolio Test has the same buying power as approximately $4,270,000, and the $200,000 threshold in the Initial Margin and Premiums Test has the same buying power as approximately $427,000.'"
Failure mode: inference_drift
Substrate document: R4-FINAL_RULE-00021
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 financial economist preparing testimony for a Congressional briefing on regulatory inflation adjustment has asked you — AI Labs." Citation ID: RLB-H-US-CFTC-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-Q011-Sonnet46. RegLegBrief AI Hallucination Research, published 2026-06-11. https://reglegbrief.com/regulators/j1/us/cftc/cpo-cta-regulation-4-7-qep-thresholds-2024/whitepaper/finding/US-CFTC-US-001-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-v1-011--sonnet-46-websearch/
RegLeg Specialist Panel. (2026). A financial economist preparing testimony for a Congressional briefing on regulatory inflation adjustment has asked you [Hallucination finding RLB-H-US-CFTC-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-Q011-Sonnet46]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j1/us/cftc/cpo-cta-regulation-4-7-qep-thresholds-2024/whitepaper/finding/US-CFTC-US-001-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-v1-011--sonnet-46-websearch/
RegLeg Specialist Panel, A financial economist preparing testimony for a Congressional briefing on regulatory inflation adjustment has asked you [RLB-H-US-CFTC-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-Q011-Sonnet46], RegLegBrief AI Hallucination Research (June 11, 2026), https://reglegbrief.com/regulators/j1/us/cftc/cpo-cta-regulation-4-7-qep-thresholds-2024/whitepaper/finding/US-CFTC-US-001-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-v1-011--sonnet-46-websearch/.
@misc{reglegbrief_RLB_H_US_CFTC_CPO_CTA_REGULATION_4_7_QEP_THRESHOLDS_2024_Q011_Sonnet46,
author = {RegLeg Specialist Panel},
title = {A financial economist preparing testimony for a Congressional briefing on regulatory inflation adjustment has asked you },
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-H-US-CFTC-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-Q011-Sonnet46},
url = {https://reglegbrief.com/regulators/j1/us/cftc/cpo-cta-regulation-4-7-qep-thresholds-2024/whitepaper/finding/US-CFTC-US-001-CPO-CTA-REGULATION-4-7-QEP-THRESHOLDS-2024-v1-011--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.