In 2017, the European Commission examined several industrial and commercial minority shareholdings that a company may hold in another, and found either that there was exclusive de facto control, even where there was no certainty that the shareholder would have a majority at the general meeting, or that there were unilateral anticompetitive effects. In addition to these classic cases, the Commission also, for the first time, looked at financial minority shareholdings where several companies have minority shareholders in common. When reviewing the Dow / DuPont transaction, it considered incidentally that the presence of the same investors in the capital of large companies in the sector concerned would reduce the companies’ incentive to compete with each other through innovation. Since then, the Commissioner Mrs Vestager has confirmed that this subject is ’a hot topic’ which is currently under scrutiny by her department. As the situation currently stands, however, this new theory concerning ’common ownership’, as applied in Dow / DuPont, leaves many questions unanswered.