Don't get too excited about Dow 20,000. There's plenty of uncertainty for the markets heading into 2017, according to David Lebovitz, global market strategist at JPMorgan Asset Management. "Central bank policy seems to be gradually pulling back, but expectations are for fiscal policy to play a larger role," he said. "We don't know what the incoming administration's policies are going to look like." The Dow Jones Industrial Average has been flirting with 20,000 for several sessions.