Big Four investment & finance definition

A widely used reference to the four largest public accounting firms that perform most of the external audits in the United States for large publicly owned corporations. The Big Four include PricewaterhouseCoopers, Deloitte Touche Tohmatsu, Ernst & Young, and KPMG. The group was long known as the Big Eight until it was reduced by mergers; it was called the Big Five until the Enron scandal led to the collapse of Arthur Andersen.