A company’s market power refers to its ability, whether intentional or not, to influence the market conditions in which it operates. This encompasses its capacity to set or impact the prices of the goods and/or services it offers. The Lerner index is one tool used to assess this power. The European Commission defines this concept by highlighting its economic and competitive implications. In economic terms, market power translates into a company’s ability to profitably set prices above marginal cost. In the field of competition, assessing market power relies on a structural market analysis, including determining market shares and identifying competitors offering similar or substitutable products. This analysis also considers barriers to entry or expansion, as well as the degree of innovation. Other qualitative criteria come into play, such as financial resources, vertical integration, and the diversity of products offered by the company under study.