And it appears they are becoming very successful at it.
After graduation, Romney went to work for the Boston Consulting Group, where he had interned during the summer of 1974. From 1978 to 1984, Romney was a vice president of Bain & Company, Inc., another management consulting firm based in Boston. In 1984, Romney left Bain & Company to co-found a spin-off private equity investment firm, Bain Capital. During the 14 years he headed the company, Bain Capital's average annual internal rate of return on realized investments was 113 percent, making money primarily through leveraged buyouts. He invested in or bought many well-known companies such as Staples, Brookstone, Domino's, Sealy Corporation and Sports Authority.In 1990, Romney was asked to return to Bain & Company, which was facing financial collapse. As CEO, Romney managed an effort to restructure the firm's employee stock-ownership plan, real-estate deals and bank loans, while increasing fiscal transparency. Within a year, he had led Bain & Company through a highly successful turnaround and returned the firm to profitability without layoffs or partner defections.
Romney left Bain Capital in 1998 to head the 2002 Salt Lake City Olympic Games Organizing Committee. He and his wife have a net worth of between 190 and 250 million USD.
http://en.wikipedia.org/wiki/Mitt_Romney