Photo illustration by Cheng Xin/Getty ImagesGetty ImagesMP Materials (NYSE:MP), a rare-earth materials company, has experienced a nearly 10% decline in its stock price over the last five trading days and is down approximately 30% from its peak on October 14, when China imposed additional restrictions on certain rare-earth exports. This drop occurs in the context of optimism surrounding a possible U.S.-China trade agreement, with President Donald Trump and Chinese President Xi Jinping scheduled to meet in So ...