Private equity firms are apt to seek scale in their portfolios. The greater the market share of a company, the more profitable the investment, the wisdom generally goes. And while this is generally true for product sectors, this relationship doesn’t hold up for medical technology or pharmaceuticals, according to research from Bain & Company. "A broad range portfolio player is not as valuable as taking a leadership position in the categories in which you participate, said Nirad Jain, a partner in Bain & Company's New York office and co-author of Bain's latest Global Healthcare Private Equity Report.