Private equity firms cashed out of car rental company Hertz in March, but now the company is adopting a shareholder rights plan in an attempt to thwart a potential activist investor. And Marvell Technologies has a big private equity firm to count among its shareholders now--as well as a single-digit boost heading into the open. Jim Cramer's Action Alerts pick is one stock that already has an activist investor--the question is, now, will it take on a big share buyback? Jonathan Marino at the Nasdaq Market Site.