Billionaire Bonderman Family Steps into Activism Fray

Shareholder activism has expanded well beyond the stereotypical irate hedge fund manager, pounding his fists on the table for corporate changes. Mutual funds have started agitating publicly, as have pension funds. And on Friday, even a prominent family stepped into the ring. Wildcat Capital — which manages $1.79 billion for David Bonderman, the founding partner of the private equity firm TPG Capital, and his family – is seeking a corporate-governance overhaul at Sorrento Therapeutics, a developer of cancer treatments based in San Diego. The stock of Sorrrento, a biotech company, has plummeted more than 75 percent since July, to a $220 million market valuation. The move is an uncommon one for a family office, which is a professional investment manager for a wealthy family. Given that such offices do not manage outside capital as a hedge fund or mutual fund would, and that they deal with the finances of billionaires, their activities are often private. Wildcat Capital, which owns 2.5 million shares, or 6.5 percent, of Sorrento, took that rare step on Friday, calling out “egregious” actions undertaken by Sorrento’s management and board in a letter it publicized. The family office, led by Leonard A. Potter, demanded that the board fire Sorrento’s chief executive, put a halt to the remainder of a private placement, appoint three new directors and hire an investment