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.

U.S. government bonds and the value of the U.S. dollar sinking is unusual because Treasurys and the dollar have historically strengthened during episodes of nervousness.

When politics interferes with the central bank’s ability to set monetary policy, inflation tends to be the result.