In the United States v. Reading Company case of 1912, the Supreme Court ruled that the Reading Company, a railroad company, had violated antitrust laws by acquiring control over competing coal companies through stock ownership. The court found that this acquisition was not merely an investment but rather a means to restrain trade and monopolize commerce in violation of the Sherman Antitrust Act. This decision marked one of several early 20th century cases where courts began to interpret corporate stock acquisitions as potential violations of antitrust law if they led to reduced competition or market dominance. It set important precedents for future interpretations and applications of U.S anti-monopoly legislation.

In the dissenting opinion for United States v. Reading Company, Justice Holmes disagreed with the majority's interpretation of the Sherman Act and its application to this case. He argued that it was not unlawful per se for a company to acquire stock in other companies, even if those companies were competitors. According to him, such acquisitions could only be considered illegal under the Sherman Act if they resulted in an unreasonable restraint of trade or attempted monopoly. In his view, there was no evidence presented that demonstrated any actual adverse effect on competition from these stock purchases by Reading Company; therefore he believed they should not have been deemed as violations of antitrust laws. Furthermore, he contended that merely owning stocks does not necessarily equate to controlling another company’s business decisions or policies - a crucial point overlooked by the majority ruling.