A potential ban on scrap metal imports in China could be a boon for imported refined copper in that country, the world's biggest consumer of the metal.
The price of copper shot up more than 2 percent in trading Wednesday, rising for the fourth straight day to the highest level in more than two years.
China is considering banning imports of scrap metal starting at the end of next year. If it follows through, demand for imported refined copper could increase. China makes up almost half of the world's copper consumption, importing about 23 million tons this year.
Mining and materials stocks reacted by gaining in midday trading Wednesday, led by U.S. giant Freeport-McMoRan, up 2 percent. Newmont Mining also rose 2 percent, Southern Copper Corp was up 0.5 percent and BHP Billiton Limited was up nearly 2 percent.
Copper is up more than 5 percent this week, as trading in the metal saw the biggest volumes since November. Copper's move past key technical levels furthered the rallying, as additional buying added on to the boost.
-- Fred Imbert and Reuters contributed to this report.