Benchmark and retrieval system · arXiv preprint 2604.19298

IndiaFinBench

406 expert-annotated questions over SEBI circulars and RBI master directions, a hybrid retrieval stack built for identifier-heavy regulatory text, and a public demo.

Rajveer Singh Pall · 2026

ProblemFinancial-NLP resources are built on Western filings. Indian regulatory text had no evaluation set, and it is dense with identifiers that semantic search alone retrieves badly.
ApproachAnnotate 406 questions over 192 SEBI and RBI documents across four reasoning types, then build a retrieval stack that fuses dense and lexical search with reciprocal rank fusion.
ResultHybrid retrieval reaches Recall@5 0.785, 9.7 points above dense-only on this corpus, and the dataset, demo and code are public.
SignificanceRegulatory text rewards exact identifier matches, so the lexical signal has to stay in the loop. The evaluation questions the benchmark raises are handled in the paper.

The dataset

406 expert-annotated items drawn from 192 source documents: SEBI circulars and RBI master directions, the instruments that actually govern Indian markets. Each item is written against a passage, with the answer and the qualifying context recorded alongside it, and the set is split across four kinds of reasoning a compliance reader has to do.

Regulatory interpretation174 items
Numerical reasoning92 items
Temporal reasoning78 items
Contradiction detection62 items

The retrieval stack

Indian regulatory text is full of exact handles: Section 51A, RBI/2025-26/251, FEMA 6(R). Dense embeddings blur them, so the stack runs BM25 and a FAISS dense index side by side and fuses the two rankings with reciprocal rank fusion. Chunking at 1,600 characters follows the paragraph structure of the source documents; both halves return five chunks.

Hybrid: dense + BM25, RRF0.785
BM25 only0.764
Dense only0.688

Recall@5 on the 24 queries that carry ground-truth chunk ids. Fusion costs ranking sharpness: BM25 alone still has the better MRR (0.674 against 0.640), because when it finds the right chunk it ranks it higher. Doubling k to ten changes neither recall nor MRR, which says the misses are corpus artefacts rather than rank-order problems.

What is public

The dataset, the demo and the code are open, so the benchmark can be re-run rather than taken on trust.

The paper

The preprint evaluates twelve models zero-shot. Every model beats a non-specialist human baseline of 69.0%, numerical reasoning separates the models most with a 35.9-point spread, and bootstrap testing finds three statistically distinct tiers. The full write-up, with its limits, lives on the research site.