A wheel loader takes ore to a crusher at the MP Materials rare earth mine in Mountain Pass, California, U.S. January 30, 2020.Stocks tied to rare earth minerals jumped Friday after President Donald Trump threatened countermeasures against China, accusing Beijing of holding the world "captive" over the metals."I will be forced, as President of the United States of America, to financially counter their move," Trump said on his social media plaftorm Truth Social. "One of the Policies that we are calculating at ...