The trade war between the United States and China is heating up and is leading investors to gobble up rare earth mineral stock MP Materials (MP 18.65%), which operates the only rare earth mine and processing facility in the United States. As of 11:25 a.m. ET, shares of MP Materials have soared 22.7%, while the S&P 500 (^GSPC 0.24%) has jumped 1.1%.The only opportunity to buy American (sort of)Throughout the morning, there have been reports emerging that suggest President Donald Trump plans to announce an ex ...