Leading consulting firms in the U.S. in 2020, by prestige rating
The Big Four
Of all the consultancy firms, the best known are the Big Four, accounting for almost 40 percent of the global market - Deloitte, PwC (Pricewaterhouse Coopers) , EY ( Ernst & Young) and KPMG. All four primarily provide financial consulting services such as taxation, audit, and risk advisory. Together they dominate the financial segment of the U.S. consultancy market.
The broader consulting market
While the global accounting firms may have the biggest, financial advisory services is only one segment of the global consulting services market. Management consulting services, broadly conceived of as including the operations, strategy, and human resources segments, constitute over half of the global market. The remainder of the market is comprised of various IT-related services.