What is the relationship between Glencore and mining in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Glencore (Xetra: A1JAGV - news ) and Anglo American (LSE: AAL.L - news ) were the top fallers after Investec (LSE: INVP.L - news ) said the challenging environment for the sector calls into question the equity value of the mining companies.
industry