Utilize the input text as a context reference, choose the right relationship between iShares and BlackRock 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.

Funds from Schwab (its U.S. Small Cap ETF , SCHA ) and BlackRock (its iShares Russell 2000 , IWM ) are so efficient that their costs are negative.How does a fund wind up with a negative cost number?

Answer: operator