Definition of antitrust law

laws that are designed to keep markets competitive, rather than allowing them to be dominated by monopolists. The main U.S. antitrust law is the Sherman Antitrust Act. Section 1 of this law makes it illegal for sellers of a product to join together to raise the price of the product. Section 2 makes monopolizing acts illegal. However, it does not automatically make having a monopoly illegal, since an inventor with a patent has a legal monopoly on that invention. It is illegal to acquire a monopoly through anticompetitive means, but the exact meaning of the law depends on how the courts interpret it. An antitrust case was filed against IBM in 1969 because of its dominance of the mainframe computer market in the 1960s. The case dragged on until 1982 when it was finally dropped because the technology had changed so much that it was no longer relevant.