He was one of the first money managers to deploy factor-investing strategies at his firm Gerstein Fisher, but now Gregg Fisher is trying something new: A quantitative approach to picking stocks of innovative small-cap companies at his new shop Quent Capital. Fisher joined this week’s “What Goes Up” podcast to discuss why he’s shifting to a more-active style of investing and how, despite his subsequent success, he wishes he could buy back that old drum set he sold for $900 in order to purchase a computer and start his first firm in the 1990s.