Shares of Molycorp Inc. ($22.42, +$1.76, +8.52%) and other rare-earth miners
jumped Wednesday as investors digested news from China that the government
intends to tighten production and crack down on illegal mining. While not
new themes, investors heeded the news as China dominates the market for rare
earths--often used in high-tech gadgets--and tightly controls output.
Supply and demand for rare-earths and any reports that speculate on changes
to that relationship can affect pricing and ultimately, stock performance.