Copper prices have been tumbling since early June as a tit-for-tat trade battle between the U.S. and China casts a shadow over commodity demand. But with the bears in charge, the market may be vulnerable to supply disruptions, including a possible strike at Escondida, the world's biggest copper mine. Bloomberg's Danielle Bochove and James Attwood discuss, with commentary from Bloomberg Intelligence's Andrew Cosgrove.