Institutional Shareholder Services, Inc. (ISS) is a proxy advisory firm. Hedge funds, mutual funds and similar organizations that own shares of multiple companies pay ISS to advise (and often vote their shares) regarding share holder votes. It is the largest such firm, with over 61 percent of the business. It was owned by MSCI until April 30, 2014 when it was purchased by Vestar Capital Partners. - Source: Wikipedia
