Grupo Mexico Goes From First to Worst on Chemical Spill

Spilling chemicals into two rivers near the U.S. border is making Grupo Mexico SAB the country’s worst performing major stock.

The shares have lost 5.3 percent, the most among 35 companies on the benchmark IPC index, through yesterday since an Aug. 6 copper sulfate solution spill at its Buenavista del Cobre mining operation that the company says contains the world’s largest copper reserves. In the prior month, it led gains among the index’s materials stock to a 16-month high 49.24 pesos.