'What happens if they stop?': Billionaire Howard Marks fears for stocks if the Fed ends its program he sees 'levitating' markets

· Billionaire investor Howard Marks questioned whether the stock market's recent rally can continue once the Fed stops "levitating markets."
· He told CNBC in an interview this week: "What happens if they stop and will they stop doing it forever?"
· The Fed has pursued a number of policies such as issuing $2.3 trillion in...