In the context of the input sentence, determine the relationship between 'Glencore' and 'BlackRock'.
Options: brand, owned by, position held, developer

BlackRock is the largest shareholder in BHP Billiton, Barrick Gold, Newmont Mining, Freeport and McMoran and South32, and is among the top four shareholders in each of Rio Tinto, Peabody Energy, Fortescue Metals Group, Glencore and Anglo American.
owned by