After a rocky couple of weeks, the price of copper has had its biggest gain of the year as investors hope for economic stimulus from China.
Copper has fallen sharply this month, and is down 7 percent since March 6, when it traded at $3.22 a pound. On Tuesday, the heavily traded May contract for copper rose 6 cents, or 2 percent, to $3.01 a pound.
Traders are hoping that the metal's recent slide may be ending and that China will take more action to shore up its economy. China is a huge importer of copper and tends to use more of it when its manufacturing sector is thriving.
Other metals were mixed. Gold edged higher and silver fell.
Crude oil edged lower and natural gas futures rose.