Steve Mandel has quietly given up the reins at Lone Pine Capital after two decades of market-beating returns. : This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues, clients or customers visit http://www.djreprints.com. Big names like Peter Lynch, David Einhorn, and Bruce Berkowitz are today either fuzzy memories or else they’ve gone through enough rocky patches to tarnish their once-stellar track records. Yet in a little noticed move, the most successful fundamental stock picker of them all quietly stepped down as portfolio manager last month—Steve Mandel of Lone Pine Capital.