For anyone who’s spent the last two years watching AI promise to revolutionize everything from radiology to restaurant reviews, here’s a sobering data point from the world of finance: a comprehensive academic study found that large-language-model trading strategies failed to beat the oldest trick in the investing playbook. Just buying and holding.

The research, titled “Can LLM-based Financial Investing Strategies Outperform the Market in Long Run?”, tested AI-driven trading approaches across more than 20 years of market data and over 100 stock symbols. The conclusion was blunt. LLM strategies consistently underperformed a simple buy-and-hold benchmark.

What went wrong with the AI traders

During bullish…