 Among the largest firms in that ranking were AlpInvest Partners, Ardian (formerly AXA Private Equity), AIG Investments, Goldman Sachs Private Equity Group, and Pantheon Ventures.Because private equity firms are continuously in the process of raising, investing, and distributing their private equity funds, capital raised can often be the easiest to measure.Other metrics can include the total value of companies purchased by a firm or an estimate of the size of a firm's active portfolio plus capital available for new investments.