This year’s MaCCI Competition and Regulation Day was hosted by the law department at the University of Mannheim. The workshop provides an annual platform for members of the departments of law and economics as well as ZEW serving to strengthen the ties between members of the university active in research related to competition and regulation. It also serves to gather feedback and improve the quality of the papers presented. Due to the pandemic the workshop was moved online and shortened slightly. The papers presented dealt with predation, algorithmic pricing, the EU commission's „New Competition Tool“ and the sanctioning of cartels.