Goldman Sachs, Affirm, and Netflix are some of today's picks: Pro Market Movers Jan. 31

Jim Cramer, David Erickson of Wharton, Christopher Brendler of DA Davidson, Jason Bazinet of Citi, Jeff Richards of GGV Capital, Pierre Ferragu of New Street Research, Adam Parker of Trivariate Research, Joe Terranova of Virtus Investment Partners, Steve Weiss of Short Hills Capital, and Jeff Kilburg of Sanctuary Wealth explain why they are buying, selling, or holding specific stocks and ETFs.