There’s nothing illegal about having a monopoly, but by the same token, you don’t have to have a monopoly to run afoul of antitrust regulation. This is an overs

There’s nothing illegal about having a monopoly, but by the same token, you don’t have to have a monopoly to run afoul of antitrust regulation. This is an oversimplification, but the Sherman Act was about monopolies, while its later companion the Clayton Act was about anticompetitive practices.