Monday put investors in lithium and rare earth metal stocks on the edge. While Standard Lithium (NYSEMKT: SLI) and Lithium Americas (NYSE: LAC) sank 10.7% and 13.3%, respectively, by 2:30 p.m. EDT, rare earth stock MP Materials (NYSE: MP) was down 8.5% by then. With concerning news from China and an electric-vehicle (EV) manufacturer slashing its outlook on supply shortages hitting electric-vehicle stocks hard, lithium and rare earth stocks were bound to feel the heat.