Rare-earth stocks -- that is, companies who mine or process any of the 17 silvery-white heavy metals crucial for tech and green energy -- have been some of the market's biggest winners over the last year.Just consider this: Since April 2025, the VanEck Rare Earth and Strategic Metals ETF, which includes MP Materials, has generated over 5 times the return of an index fund tracking the S&P 500.One rare-earth stock that is noticeably missing from that popular metals exchange-traded fund (ETF), however, is USA ...