The price of copper rose to a 20-month high on Monday, on worries a strike at the world's leading copper mine in Chile will affect the global supply.
The price per pound (roughly equivalent to half a kilo) rose to 2.77 U.S. dollars on the London Metal Exchange, a 4.07 percent increase over the previous price of 2.66 dollars.
"Copper futures rallied to the highest level since May 2015 ... amid concerns over an ongoing strike," according to the website Investing.com.
Miners at northern Chile's Escondida mine walked off the job on Thursday, after their demands for wage increases were rebuffed.
The Anglo-Australian mining giant BHP Billiton, which owns a controlling share of the mine, announced it would shut down operations at the world's biggest copper producer for a month.
On Monday, the company said it could not meet its delivery obligations due to the strike. Escondida produces five percent of the world's supply of copper.