The way capital is distributed in a company does not always match the actual power dynamics within it. Shareholders traditionally have voting rights, but this does not always mean that owning shares directly translates to controlling corporate decisions. The history of large corporations shows that ownership and control can diverge. In the United States, this phenomenon was highlighted by Adolf Berle and Gardiner Means in the early twentieth century. They observed that as large companies grew, the number of shareholders increased, and each individual's stake became smaller. This made it harder for shareholders to collectively influence management, even though they retained legal voting rights. As a result, control often shifted to company managers. This separation between ownership and control laid the groundwork for agency theory, which examines the potential for conflicts of interest between those who own assets and those who manage them. Corporate governance laws have since evolved to address these issues by trying to monitor and control managerial behavior. In France, the situation has historically been different. French companies have traditionally had a more concentrated shareholding structure, often involving families, industrial groups, financial institutions, or even the state. This concentration allowed for a "reference shareholder" who could monitor management more effectively than the dispersed ownership model seen in the United States. French corporate governance literature has often emphasized an internal control model, contrasting it with the external control model typical of Anglo-American markets. However, this concentration does not eliminate governance challenges; it merely shifts them. A major shareholder may have stronger incentives to monitor management, but their power can also be used in their own interest, potentially at the expense of other shareholders. This dynamic has shaped the French legal framework, which distinguishes between economic participation and the actual ability to influence company decisions. Recent developments in both the United States and France have altered traditional models of shareholding. In the U.S., while economic ownership remains dispersed, the exercise of shareholder rights has increasingly fallen to institutional investors such as pension funds and asset managers. This has led to what Ronald Gilson and Jeffrey Gordon call "agency capitalism," where the separation between ownership and control is compounded by another layer: the distinction between the economic beneficiary and the entity that exercises voting rights on their behalf. In France, the presence of reference shareholders has not disappeared, but international investment, collective management, and portfolio diversification have changed the landscape of large listed companies. By the end of 2024, non-residents held half the capital of the thirty-five largest French companies, and much of this was in the form of portfolio investment, making it harder to describe the French market solely through the lens of a dominant shareholder. The comparison between the U.S. and France reveals that the traditional contrast between concentrated and dispersed ownership is no longer sufficient to explain the evolution of corporate power. In the U.S., economic ownership remains dispersed, but the exercise of rights has become concentrated in institutional investors. In France, concentrated ownership coexists with increasing internationalization and institutionalization. Both systems show that the location of power is not determined solely by the distribution of capital. French law, in particular, has evolved to address these complexities by recognizing the social interest of the company alongside the economic interests of shareholders. This legal framework highlights the need to consider not only who owns shares but also who exercises the rights attached to them, for what purpose, and under what limits. The evolution of shareholder power thus calls for a renewed legal analysis that goes beyond the traditional separation of ownership and control.