The European Central Bank has introduced an AI-based indicator that uses Reddit posts to track retail investor sentiment across market topics and individual assets. The ECB says changes in the measure are associated with next-day equity returns, particularly during market downturns.
In a blog post published on 12 November 2026, ECB authors Fabian Wagner and Julian Metzler said the Reddit Retail Investor Sentiment Indicator (R-RISI) provides more timely, higher-frequency information on short-term market dynamics than survey-based measures. They presented it as a way to track shifts in investor mood, not as a forecast of returns.
The indicator uses OpenAI’s ChatGPT 5.1 to classify Reddit posts by sentiment, topic and stock ticker or alternative asset. Sentiment is labelled positive, negative or neutral. Topics include equities, funds, macroeconomics, options, commodities, geopolitics, tariffs and crypto-assets. The results can be broken down by topic, security or asset group.
The researchers draw on popular investing and economics communities, including r/wallstreetbets, r/stocks, r/investing and r/Economics. The ECB says a language model can use context to identify companies or assets when users refer to them informally, rather than relying only on ticker symbols or keyword matching.
To calculate the overall measure, the researchers compare weighted positive and negative posts. Posts are weighted using the logarithm of their comment count and Reddit score. The indicator is based on the difference between rolling 365-day standardised measures of positive and negative posts. Values above zero indicate sentiment that is unusually positive relative to the previous year; values below zero indicate unusually negative sentiment.
The ECB’s examples show that sentiment can differ across topics. Tariff-related posts pushed the overall measure sharply lower during market turmoil in April 2025. In the topic-specific series, the announcement of US reciprocal tariffs coincided with a sharp drop in macroeconomic sentiment, while the geopolitics measure reacted less.
The authors also compared sentiment measures for artificial-intelligence-related stocks and Bitcoin with their market prices. Reddit discussion of the “Magnificent Seven” technology companies became more prominent after ChatGPT was released on 30 November 2022. The ECB says the AI-related sentiment measure broadly tracked the performance of a basket of those companies, though it was more volatile than prices.
For Bitcoin, the Reddit sentiment measure turned markedly negative during the crypto-asset downturns of 2017–18 and 2022–23, then improved during stronger market phases. The ECB said sentiment and Bitcoin prices diverged more often than in the AI-stock comparison, and the sentiment measure was also more volatile.
The ECB said a companion paper contains a breakdown of the indicator and full empirical results. Its live dashboard provides interactive views of sentiment by market, topic and selected asset.
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