Leveraging Large Language Models for Institutional Portfolio Management: Persona-Based Ensembles
Yoshia Abe, Shuhei Matsuo, Ryoma Kondo, Ryohei Hisano
TL;DR
This work evaluates large language models for institutional portfolio management by predicting price movements of a stocks-and-bonds portfolio and adjusting positions accordingly. It examines how different investor personas within LLMs, combined via mode ensembles, affect predictive accuracy and downstream investment performance. The study finds that LLM-driven strategies outperform Buy-and-hold on the Sharpe ratio during rising CPI periods, while traditional approaches can outperform during CPI declines or sharp drawdowns; results vary across other metrics and market regimes. The findings suggest LLMs can augment institutional decision-making, particularly when paired with regime-aware ensembles and complementary strategies to handle diverse market conditions.
Abstract
Large language models (LLMs) have demonstrated promising performance in various financial applications, though their potential in complex investment strategies remains underexplored. To address this gap, we investigate how LLMs can predict price movements in stock and bond portfolios using economic indicators, enabling portfolio adjustments akin to those employed by institutional investors. Additionally, we explore the impact of incorporating different personas within LLMs, using an ensemble approach to leverage their diverse predictions. Our findings show that LLM-based strategies, especially when combined with the mode ensemble, outperform the buy-and-hold strategy in terms of Sharpe ratio during periods of rising consumer price index (CPI). However, traditional strategies are more effective during declining CPI trends or sharp market downturns. These results suggest that while LLMs can enhance portfolio management, they may require complementary strategies to optimize performance across varying market conditions.
