Copper futures advanced, approaching $14,500 per ton in London, placing the metal on track for its third consecutive monthly increase. This surge is largely attributed to heightened supply-risk concerns.

The immediate cause for this concern is the rejection by workers at Antofagasta's Centinela mine in Chile of the company's latest wage offer. This action significantly raises the likelihood of a strike at this crucial copper operation, which would further constrict the global copper supply and likely push prices higher.

Separately, supervisors at BHP's Escondida mine, the world's largest copper mine, are also urging members to reject a contract offer, setting the stage for a potential strike there as well. These labor disputes in major copper-producing regions of Chile are creating a bullish environment for copper prices. The market sentiment regarding copper is currently described as mildly positive.