An AMF study finds that social media increasingly influences retail trading in CAC 40 shares, particularly among younger investors and neo-broker clients, who respond more strongly to post volumes than to sentiment or fundamentals.
AMF Study Finds Social Media Playing a Growing Role in Young Investors’ Decisions
The French Financial Markets Authority (AMF) published a study on 15 July 2026 examining how retail investors trade CAC 40 shares in the social media era. The AMF noted that, as retail investing grows, the ways in which investors obtain information and support are changing. Although bank advisers remain the primary source of information, social media is playing an increasingly important role in investment decisions, particularly among younger investors. (Source: AMF, The Influence of Social Media on Retail Investor Trading in CAC 40 Stocks; published: July 2026)
Data Background: Differences in Information Sources by Age Group
Retail share trading has increased in recent years, while financial and investment-related topics have attracted growing attention on social media. Two key data points illustrate how this trend differs across investor groups:
According to the AMF’s Savings and Investment Barometer published in December 2025, 12% of French investors consult the social media accounts and posts of financial institutions before investing.
Among less experienced investors aged 18 to 24, 41% said they obtained information through this channel, according to research conducted for the AMF by the Organisation for Economic Co-operation and Development (OECD) and published in November 2023.
Analytical Framework: Comparing Behaviour by Age and Intermediary Type
The study aimed to analyse the influence of the social media platform X, formerly known as Twitter, on the trading activity of retail investors directly holding CAC 40 shares between January and November 2024. Social media activity was measured using the daily number of posts on X and the sentiment expressed in them, whether positive, negative or neutral. Based on transaction reporting data submitted to the AMF, the study was able to compare investor behaviour across two dimensions:
By age, comparing investors aged over 35 with those under 35.
By type of trade execution intermediary, distinguishing between traditional banks, online-only banks and neo-brokers.
The analysis treated social media as a potential source of information influencing investors, while also assessing the effects of more fundamental variables, including share prices and corporate communications from issuers.
Key Finding: Younger Clients Are More Sensitive to Social Media Information
The study found that French retail investors generally buy when share prices fall and sell when prices rise. This contrarian behaviour is consistent with previous academic research and may reflect a desire to realise profits. Retail investors also tend to become more active when market volatility increases. One notable finding was that investors were more sensitive to the volume of posts than to their content. The AMF stated in the report:
The tone of posts—whether they express positive or negative views—does not appear to influence trading activity.
The study further found that younger investors and those most familiar with digital tools were the most responsive to social media. These groups generally reacted insufficiently to fundamental information, such as prices or issuer announcements, and their behaviour was less sensitive to the economic environment. By contrast, online bank clients were the most likely to adjust their behaviour in response to fundamental information.
Comparison of Social Media Responsiveness Across Investor Groups
| Investor Group | Response to Social Media | Response to Fundamentals | Observation Period |
|---|---|---|---|
| Younger investors/neo-broker clients | Overreact, with activity increasing by up to twice as much as that of other investors | Underreact | January to November 2024 |
| Online bank clients | Relatively sensitive | Most likely to adjust accordingly | January to November 2024 |
| Traditional bank clients | Least responsive | Relatively stable | January to November 2024 |
More specifically, younger investors and neo-broker clients displayed an excessive response to information posted on social media. When the volume of posts increased, either only this group became more active, or, when activity rose across all investors, their response was more pronounced, with their activity increasing by twice as much as that of other investors. Traditional bank clients were the least responsive to social media, which is consistent with the likelihood that they are more experienced investors who use social media less frequently.
Research Supports the Investor Protection Strategy
The AMF said the findings highlighted the importance of continuing to support investors, particularly younger investors, by encouraging them to conduct thorough research before investing and consult reliable and diverse sources of information. As part of related initiatives, the AMF worked with the French advertising self-regulatory authority (ARPP) in 2023 to introduce a Responsible Influence Certificate for the financial sector.
Frequently Asked Questions About the AMF Social Media Study
What is the main conclusion of the AMF study?
The study found that social media is playing an increasingly important role in retail investment decisions. Younger investors and neo-broker clients overreact to social media information while underreacting to fundamentals. Investors are more sensitive to the volume of posts than to their content, and whether posts are positive or negative does not appear to affect trading activity.
What data and investor groups did the study analyse?
The study used transaction reporting data submitted to the AMF to analyse the behaviour of retail investors directly holding CAC 40 shares between January and November 2024 in relation to activity on the social media platform X. Investors were compared by age, using 35 as the dividing point, and by intermediary type, covering traditional banks, online-only banks and neo-brokers.
Which groups are most and least sensitive to social media?
Younger investors and neo-broker clients are the most sensitive, with their activity increasing by up to twice as much as that of other investors during periods of higher market activity. Traditional bank clients are the least responsive, which is consistent with the possibility that they are more experienced and use social media less frequently. Online bank clients are the most likely to adjust their behaviour in response to fundamental information.
What measures has the AMF taken in response to these findings?
The AMF is using the study to support its investor protection strategy, encouraging investors, particularly younger people, to conduct thorough research and consult reliable and diverse information sources before investing. In addition, the AMF worked with the advertising self-regulatory authority ARPP in 2023 to introduce a Responsible Influence Certificate for the financial sector.
