Dr Madelaine’s work examines why institutional investors choose to disseminate information and how this affects the behaviour of other investors. He also studies mandatory short-selling disclosures, showing, for example, that such disclosures can encourage shorted firms to distribute higher dividends.
Recently, he has analysed the consequences of retail investors’ use of financial forums. Many widely shared messages combine financial knowledge with references to popular culture and can encourage collective action among internet users. This dynamic was illustrated by the GameStop episode in 2021, when a social media-driven short squeeze led by retail investors from Reddit pushed the stock price up by more than 1,700%, inflicting billions of dollars in losses on hedge funds.
A positive impact on financial markets
“I’m very proud and honoured to receive this award,” says Dr Madelaine. “My interest in financial markets developed early on after observing the consequences of the subprime crisis, which highlighted the economic and social costs of market failures.
“Across my research projects, I seek not only to advance academic knowledge but also to draw lessons that may inform regulators, practitioners, and policymakers. Ultimately, my goal is to contribute to better-functioning financial markets and to have a positive impact beyond academia.”
The AMF is an independent public authority responsible for ensuring that savings invested in financial products are protected and that investors are provided with adequate information. The AMF also supervises the orderly operations of markets. It launched the Young Researcher Award in 2015 to support academic research on topics related to regulation and the financial markets.
Dr Madelaine officially received his €5,000 prize on 30 January 2026, at the AMF Scientific Advisory Board meeting, during which he presented the results of his research.
