Utilize the input text as a context reference, choose the right relationship between Glencore and mining from the options. Options: 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.

Answer: industry