Chenri Luo | Searcharxiv

arXiv2026

LLM-Generated Investment Research Memos Need Validation

LLMs are increasingly adopted to draft long-form investment research memos, but their reliability is judged claim by claim, while readers read each memo as a whole. In this paper, we show that a low claim-level error rate does not necessarily mean that a memo is reliable: even with a refutation rate of just 1-2%, roughly four in ten memos contain at least one claim contradicted by official filings. First, we generate 1,440 memos with four recent LLM-powered agents for 30 companies over 12 quarters, decompose them into 77,272 financial claims, and verify each against the same official source bundle by retrieving evidence, matching it to the claim, and verifying the outcome. Second, we find that only 1.17-1.77% of claims are refuted, yet 36.94-41.11% of memos contain at least one refuted claim, and agents differ in severity: Codex has the lowest memo-level rate; a qualitative review further groups errors into four patterns (time, unit, context, concept).

cs.CE↗

arXiv2026

FinTagging: Benchmarking LLMs for Extracting and Structuring Financial Information

Accurate interpretation of numerical data in financial reports is critical for markets and regulators. Although XBRL (eXtensible Business Reporting Language) provides a standard for tagging financial figures, mapping thousands of facts to over 10k US GAAP concepts remains costly and error prone. Existing benchmarks oversimplify this task as flat, single step classification over small subsets of concepts, ignoring the hierarchical semantics of the taxonomy and the structured nature of financial documents. Consequently, these benchmarks fail to evaluate Large Language Models (LLMs) under realistic reporting conditions. To bridge this gap, we introduce FinTagging, the first comprehensive benchmark for structure aware and full scope XBRL tagging. We decompose the complex tagging process into two subtasks: (1) FinNI (Financial Numeric Identification), which extracts entities and types from heterogeneous contexts including text and tables; and (2) FinCL (Financial Concept Linking), which maps extracted entities to the full US GAAP taxonomy. This two stage formulation enables a fair assessment of LLMs' capabilities in numerical reasoning and taxonomy alignment. Evaluating diverse LLMs in zero shot settings reveals that while models generalize well in extraction, they struggle significantly with fine grained concept linking, highlighting critical limitations in domain specific structure aware reasoning.

cs.CL↗