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.

Mining groups BHP Billiton (NYSE: BBL - news ) , Glencore (Xetra: A1JAGV - news ) , Antofagasta (Other OTC: ANFGF - news ) and Rio Tinto (LSE: RIO.L - news ) were down between 2.3 and 4.7 percent.

Answer: industry