This article analyzes the effects of the acquisition of the Port of Piraeus by the Chinese shipping operator COSCO in July 2016 on the organization of container traffic in Europe. Using real-time container ship positions provided by vessel tracking systems between 2015 and 2019, we study the impact of the privatization of the Greek port on its attractiveness and on that of competing ports for the ships of the various operators, and more particularly of COSCO. Difference-in-difference estimates suggest that the number of container ship calls to the Port of Piraeus has increased following its privatization, but that this increase in attractiveness corresponds mainly to vessels operated by COSCO with a capacity of more than 3000 twenty-foot equivalent units, and in particular to the largest of them. We do not identify any crowding out effect between operators in Piraeus: the use of Piraeus by the vessels of other operators remains relatively unchanged. The privatization of Piraeus seems to have imposed the Greek port as COSCO's transhipment hub for the European market without this being to the detriment of ports in any other particular European area.