Sam Levenson once observed, “The reason grandparents and grandchildren get along so well is that they have a common enemy.”

The same could be said for a new alliance between groups who have often been at odds and more often had no communication at all: large institutional shareholders and corporate directors. A new initiative called SDX is prompted in part by a mutual interest in combating “activist shareholders” whose short-term pressure for performance is detrimental to both corporations and long-term investors. SDX founders include representatives from Vanguard, BlackRock and the Florida state pension fund as well as directors of JP Morgan Chase, Korn/Ferry and Six Flags. This is the kind of alliance that made it possible for Apple to resist Carl Icahn’s six-month siege pushing the company to use their cash hoard for a $50 billion stock buy-back.