New equity-research benchmark ILE: GPT-6 Astra and Claude Opus 5.5 lead overall, but Astra scores 52.5 on Forecast & Model

[HF Papers] A paper titled Investor's Last Exam introduces ILE, an equity-research benchmark designed by experienced buy-side investors and fund managers, according to the authors. It combines a versioned financial database spanning 3.43 million document versions across nine source categories plus structured market data, with validated timestamps governing retrieval and computation; a task taxonomy built around professional analyst deliverables; and an expert-led scoring framework linking criteria to sources, calculations and assumptions through financial dependency graphs. Evaluation spans 86 assignments and jointly assesses research quality, forecast accuracy and simulated investment performance. The authors report that GPT-6 Astra and Claude Opus 5.5 lead overall at 68.1 and 66.9 out of 100, yet even Astra scores only 52.5 on Forecast & Model. They conclude that even state-of-the-art models fail to translate overall research capability into predictive performance. The work is a preprint and has not been peer-reviewed.