MP Materials has seen a huge increase in interest in its business, but the big story is that the interest is from more than just investors.MP Materials (MP 4.24%) went public a few years back via a merger with a special purpose acquisition corporation (SPAC). Like many SPAC deals, there was initial excitement that eventually cooled off. At least until 2025, when MP Materials' unique focus led to a big investment from the U.S. government.The business appears to have a huge growth opportunity ahead of it. Wha ...