Premarket: European stocks struggle, dollar near three-year low, gold hits US$3,500

European stock markets edged lower on Tuesday, after U.S. President Donald Trump's attack on the Federal Reserve chair sparked a selloff of U.S. assets, putting fresh pressure on Treasuries, while gold hit a new record high. Trump stepped up his criticism of Fed Chair Jerome Powell for not cutting interest rates, calling him a "major loser," in a social media post on Monday , which raised concerns about the president's influence over the central bank. Wall Street indexes lost around 2.4% on Monday and the dollar hit its lowest in three years. U.S. Treasury yields rose as traders worried that…