In the United States v. E.I. Du Pont De Nemours & Co., 1955, the U.S Supreme Court ruled that DuPont's acquisition of a significant percentage of General Motors (GM) stock constituted an antitrust violation under Section 7 of the Clayton Act. The court found that this acquisition could potentially reduce competition in the automobile finishes and fabrics market where both companies were dominant players. Despite DuPont arguing that its purchase was merely a passive investment, it was determined to have violated anti-competition laws due to its ability to influence GM’s decision-making process and stifle competition within these markets through its substantial shareholding position.

In the dissenting opinion for United States v. E.I. du Pont de Nemours & Co., Justice Reed, joined by Justices Minton and Burton, disagreed with the majority's view that DuPont had violated antitrust laws through its acquisition of General Motors (GM) stock. The dissent argued that there was no evidence to suggest DuPont had restrained trade or attempted to monopolize any part of commerce related to GM. They contended that a mere stock ownership does not constitute an automatic violation of antitrust laws unless it leads to anti-competitive practices which were absent in this case according to them. Furthermore, they pointed out inconsistencies in applying the Clayton Act as interpreted by the Court; if applied uniformly all corporations owning stocks in other companies would be deemed illegal per se under Section 7 of Clayton Act which is absurd and impractical according to them.