Spain's market regulator warns AI systems make investment errors without human oversight
Spain's financial regulator CNMV published a study showing that AI systems like ChatGPT, Gemini, DeepSeek and Perplexity make errors and hallucinate when making investment recommendations, potentially causing investor losses without human oversight. The systems confused companies, provided false data, and mixed information from different periods, though performance improved with structured prompts and standardized data sources.
What happened
The Spanish financial regulator CNMV published a study analyzing how ChatGPT, Gemini, DeepSeek and Perplexity make investment decisions about publicly traded companies. The study, conducted by researchers Ricardo Cris贸stomo and Diana Mykhalyuk, found that these AI systems exhibit errors and hallucinations that without human oversight can cause investors to lose money.
When analyzing stocks in the IBEX index, the AI systems confused companies within the same group, provided non-existent stock quotation data, mixed earnings figures from different years, and incorrectly categorized some securities. The researchers noted that AI performance improved significantly when given structured prompts and standardized data sources rather than unfiltered web information.
Reported impact
The CNMV concluded that errors detected in AI investment recommendations can ultimately lead to losses for investors. The regulator stressed the necessity of expert human supervision to mitigate these risks.
Index analysis
The researchers found that large language models can potentially achieve market-beating performance, but this conclusion is qualified by significant caveats related to how the AI is prompted and what data sources it uses. Performance varied substantially depending on whether users interacted with the AI in a naive or structured manner.
Classification
Sources and evidence
Sources not yet published
This record was researched and written by the Index from original reporting. Its sources are still being verified by an editor, and they are listed here once that check is complete. Until then the record carries no reviewer.