Data-opolies and B2B Data Sharing Duties under the Scope of Digital Markets Act

This paper examines the regulatory shift in the European Union from facilitating the free flow of data to establishing rules that govern mandatory data sharing, particularly within the framework of the Digital Markets Act (DMA). Focusing on dominant digital platforms – socalled «data-opolies» – the paper explores how data concentration affects market dynamics and competition. It analyses the DMA’s data sharing duties imposed on gatekeepers, including their interplay with GDPR obligations, and reflects on the limits and opportunities for private and collective enforcement mechanisms in the absence of explicit remedies.