Premarket: U.S. futures flat amid uncertainty over consequences of Trump's call with Putin

European markets held firm on Tuesday ahead of German lawmakers voting on a landmark overhaul to government spending, while uncertainty over a call on Ukraine between U.S. President Donald Trump and Russia's Vladimir Putin kept gold at $3,000 an ounce. This month has brought a huge divergence between the performance of U.S. stocks and those elsewhere, particularly in Europe and China, where markets have seen a surge in inflows from investors that have cashed in on Wall Street's sky-high valuations. Trump's erratic approach to trade policy, coupled with his mass firings of federal employees, has stirred up uncertainty for companies,…