FLAG-TRADER: Fusion LLM-Agent with Gradient-based Reinforcement Learning for Financial Trading

Guojun Xiong, Zhiyang Deng, Keyi Wang, Yupeng Cao, Haohang Li, Yangyang Yu, Xueqing Peng, Mingquan Lin, Kaleb E Smith, Xiao-Yang Liu, Jimin Huang, Sophia Ananiadou, Qianqian Xie


Abstract
Large language models (LLMs) fine-tuned on multimodal financial data have demonstrated impressive reasoning capabilities in various financial tasks. However, they often struggle with multi-step, goal-oriented scenarios in interactive financial markets, such as trading, where complex agentic approaches are required to improve decision-making. To address this, we propose FLAG-Trader, a unified architecture integrating linguistic processing (via LLMs) with gradient-driven reinforcement learning (RL) policy optimization, in which a partially fine-tuned LLM acts as the policy network, leveraging pre-trained knowledge while adapting to the financial domain through parameter-efficient fine-tuning. Through policy gradient optimization driven by trading rewards, our framework not only enhances LLM performance in trading but also improves results on other financial-domain tasks. We present extensive empirical evidence to validate these enhancements.
Anthology ID:
2025.findings-acl.716
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
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Findings | WS
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Publisher:
Association for Computational Linguistics
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Pages:
13921–13934
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URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.716/
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Cite (ACL):
Guojun Xiong, Zhiyang Deng, Keyi Wang, Yupeng Cao, Haohang Li, Yangyang Yu, Xueqing Peng, Mingquan Lin, Kaleb E Smith, Xiao-Yang Liu, Jimin Huang, Sophia Ananiadou, and Qianqian Xie. 2025. FLAG-TRADER: Fusion LLM-Agent with Gradient-based Reinforcement Learning for Financial Trading. In Findings of the Association for Computational Linguistics: ACL 2025, pages 13921–13934, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
FLAG-TRADER: Fusion LLM-Agent with Gradient-based Reinforcement Learning for Financial Trading (Xiong et al., Findings 2025)
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https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.716.pdf