STEVEN G. MANDIS worked at Goldman Sachs from 1992 to 2004 in its investment banking, private equity, and proprietary trading areas. He assisted Hank Paulson and other senior executives on special projects and eventually became a portfolio manager in one of the largest and most successful proprietary trading areas at Goldman Sachs. Post-Goldman, he cofounded a multibillion-dollar global alternative asset management firm that was a trading and investment banking client of Goldman Sachs. During the financial crisis, Mandis was a senior adviser to McKinsey & Company before accepting a senior exec...