The dollar tumbled on Monday to its lowest level in three years as investor confidence in the U.S. economy took another hit over President Donald Trump’s attacks on the Federal Reserve chairman, potentially putting the central bank’s independence under threat.Trump ramped up his criticism of Fed Chair Jerome Powell on Monday via social media, calling him a “major loser” and demanding that he lower interest rates immediately. Against a basket of currencies, the dollar slid as low as 97.923 on Monday, its lowest since March 2022. The currency also fell to a decade-low against the Swiss franc, while the euro broke above $1.15.