ALawBench: Benchmarking Frontier Agents in IPO Legal Due Diligence

Legal due diligence for an initial public offering (IPO) requires reviewing extensive records across an issuer's corporate history, consumes thousands of lawyer hours, and demands professional judgement. Advances in frontier agents raise the prospect of conducting such matters end to end, but testing this prospect requires a realistic workspace, materials grounded in real disclosures, and rubrics grounded in legal practice. We introduce ALawBench, the first benchmark to evaluate agents on comprehensive legal due diligence for IPOs in the Chinese mainland and Hong Kong, a task usually undertaken by legal teams. Its legal workspace combines scanned documents, corporate databases with controlled distractors, and professional tools for the full IPO due diligence workflow. Built by 37 legal experts from public disclosures, ALawBench comprises 63 matters, 12,151 PDFs, 30,243 pages, and 15,557 rubrics. The rubrics measure diligence through review, verification, and report delivery, and judgement through risk identification and professional assessment. Across 21 frontier models, the best net score rate is 40.39%, and 12 models score below zero. Review, delivery, and risk identification improve with capability, but verification errors barely decline and professional assessment improves only marginally. Reading nearly all key documents leaves verification errors unchanged and adds little assessment credit. Frontier agents cannot yet deliver issuable IPO legal due diligence reports, as their diligence falls short at verification and their judgement stalls at assessment.