The pupil has become the master within BlackRock Inc.’s exchange-traded fund business, with cost-conscious investors favoring a range of cheap funds over more established products.

BlackRock’s ETF designed to offer price-efficient exposure to developed markets has outgrown its similar, more expensive fund for the first time, data compiled by Bloomberg show. The upstart -- the iShares Core MSCI EAFE ETF, known as IEFA -- now manages US$63.6 billion after adding US$522 million on Wednesday. The original iShares MSCI EAFE ETF has US$63.1 billion.

The switch is a sign of just how much cost matters. BlackRock purposefully played to that trend when it started a bunch of cheap, core-branded products in 2012 to appeal to buy-and-hold investors. Mark Wiedman, global head of iShares at the time, has said that the firm planned to make up for the lower fee revenue by attracting more assets to its funds.

“iShares is positioned to serve different client types who value different components of the ETF value proposition,” Matt Kobussen, a spokesman for BlackRock, said.

BlackRock’s original fund, known as EFA, has an extra 11 years of performance over its younger sibling and trades three times more on an average day. But while EFA charges US$3.20 for every US$1,000 invested, IEFA costs just 80 cents.

It’s not the first time one of BlackRock’s ‘core’ funds has grown more than an older ETF. Assets in the iShares Core MSCI Emerging Markets ETF, known as IEMG, surpassed the more expensive iShares MSCI Emerging Markets ETF, ticker EEM, in June 2017. IEMG is now almost double the size of EEM.