In this paper, the author reports on how the European and American Competition Authorities apprehend margin squeeze, viz. the fact for dominant undertakings operating simultaneously as vertically‐integrated entities and as downstream market participants to increase wholesale prices by reducing their retail price, thus squeezing their downstream‐market competitors out. The address of margin squeeze as distortive of competition differs significantly on either side of the Atlantic while it is a major concern for non‐dominant competitive economic operators. The divergences demonstrated in this article further attest to a fundamental opposition between EU Competition Law and American Antitrust Law.