Mitigating Look-ahead Bias in Forecasting with LLMs

How can researchers ensure that large language models (LLM), when tasked with time series forecasting, do not inject look-ahead bias and thereby inflate measured predictive power? In his brief November 2024 paper entitled "Look-Ahead Bias in Large Language Models (LLMs): Implications and Applications in Finance", Miquel Noguer I Alonso addresses sources of LLM look-ahead bias in financial time series forecasting and proposes strategies to mitigate it. Based on logic and knowledge of LLM development, he concludes that: