Same Claim, Different Judgment: Benchmarking Scenario-Induced Bias in Multilingual Financial Misinformation Detection
Zhiwei Liu, Yupen Cao, Yuechen Jiang, Mohsinul Kabir, Polydoros Giannouris, Chen Xu, Ziyang Xu, Tianlei Zhu, Tariquzzaman Faisal, Triantafillos Papadopoulos, Yan Wang, Lingfei Qian, Xueqing Peng, Zhuohan Xie, Ye Yuan, Saeed Almheiri, Abdulrazzaq Alnajjar, Mingbin Chen, Harry Stuart, Paul Thompson, Prayag Tiwari, Alejandro Lopez-Lira, Xue Liu, Jimin Huang, Sophia Ananiadou
TL;DR
This work introduces MFMD-Scen52,84,110170,46,74, a scenario-conditioned, multilingual benchmark for financial misinformation detection that varies context along three axes: persona, region, and identity. By constructing a 502-item multilingual dataset (English, Chinese, Greek, Bengali) and evaluating 22 LLMs, the study reveals pronounced behavioral biases that shift decision boundaries, are magnified in low-resource languages, and depend on complex interactions between role and identity. The framework provides both standard detection metrics and a bias estimate (AM and MAV of F1 differences) to quantify context effects, offering a rigorous basis for bias mitigation in high-stakes financial misinformation tasks. The results have practical implications for the deployment of LLMs in finance, regulators, and researchers seeking robust, fair multilingual misinformation detection. The authors also share a public repository to enable ongoing benchmarking and improvement in bias mitigation.
Abstract
Large language models (LLMs) have been widely applied across various domains of finance. Since their training data are largely derived from human-authored corpora, LLMs may inherit a range of human biases. Behavioral biases can lead to instability and uncertainty in decision-making, particularly when processing financial information. However, existing research on LLM bias has mainly focused on direct questioning or simplified, general-purpose settings, with limited consideration of the complex real-world financial environments and high-risk, context-sensitive, multilingual financial misinformation detection tasks (\mfmd). In this work, we propose \mfmdscen, a comprehensive benchmark for evaluating behavioral biases of LLMs in \mfmd across diverse economic scenarios. In collaboration with financial experts, we construct three types of complex financial scenarios: (i) role- and personality-based, (ii) role- and region-based, and (iii) role-based scenarios incorporating ethnicity and religious beliefs. We further develop a multilingual financial misinformation dataset covering English, Chinese, Greek, and Bengali. By integrating these scenarios with misinformation claims, \mfmdscen enables a systematic evaluation of 22 mainstream LLMs. Our findings reveal that pronounced behavioral biases persist across both commercial and open-source models. This project will be available at https://github.com/lzw108/FMD.
