What happened

Shares in copper miner Taseko Mines (TGB 2.52%) fell more than 9% as of 3 p.m. EDT today. Although Taseko's mining assets are nearly all in Canada (the company also has a U.S. project in Arizona), today's move is all about one country: China.

Moreover, it's not just about China; it's about the potential knock-on effect of the debt crisis at one of its largest property developers, China Evergrande Group. The market spent the weekend digesting speculation that Evergrande would default on its debt and then promptly sold the market off on Monday.

Bundle of copper wiring.

Image source: Getty Images.

Given Evergrande's debt of more than $300 billion, and the scars of investor memories from the great financial crisis, it's understandable that the market has concerns.

So what

China's property sector potentially catching a cold is not good news for the markets, and it's not good news for miners like Taseko. In a nutshell, copper is the world's most economically sensitive metal, and China's construction markets are usually the swing player in marginal demand.

Construction is the single biggest end market for copper and is responsible for around 28% of demand. In addition, construction activity influences electrical networking and transport demand. Put together, those three end markets make up more than two-thirds of copper demand

Crane on top of large construction site.

Image source: Getty Images.

Indeed, it's no accident that Taseko's larger copper mining peers like Freeport-McMoRan, Southern Copper, and Antofagasta are all down significantly today. Taseko is particularly exposed because its sole focus is copper, so there's nothing else to offset falling copper prices.

Now what

Wait and see. It's far from clear what will happen with Evergrande. A managed default or even a bailout is a possibility, and it's not known what level of contagion in the global economy would occur even if Evergrande was allowed to fail. Thus, companies with heavy exposure to copper, such as Taseko, could see better days ahead if the reality isn't as bad as the speculation.