Assessments of the bike-sharing industry traditionally focus on its effects on other markets, municipalities, or general well-being. This paper deviates from this on how the market is or-ganised. Using information on the aggregate number of firms in cities and greater cities across Europe, we found non-proportional changes in market size with respect to changes in market structure. This is crucial information inferring changes in profits, costs, or degree of product differentiation. To distinguish between these three sources, we utilised additional firm-level data on capacity and type of service provided. Our results suggest that the non-proportional increase in market size after an entry is most likely associated with increased intensity of com-petition and new forms of offered services, i.e. product differentiation. We did not find evi-dence that newcomers have been entering with substantially larger capacities per capita com-pared to incumbents. From a policy perspective, entry into the bike-sharing industry has bene-fited consumers through market expansion and caused a potential decrease in profits.