Exchange traded funds are a booming business today. Brokers, advisors, and everybodyโ€™s mother has been moving assets from actively managed funds into ETFs, but now even actively managed mutual funds are buying ETFs.

I guess since many investors now recognize that actively managed funds are nothing more than high-fee closet index funds, the โ€œportfolio managersโ€ of these funds feel they can just openly buy index based ETFs.

Marketwatch reports that in 2016 1,222 mutual funds held an ETF as a component in their portfolio. The median size of the ETF holdings were 4.5% of the portfolio. In 2006, only 595 mutual funds held an ETF, comprising 1.2% of assets.

The most widely held ETF by mutual funds, was the SPDR S&P 500 ETF.

According to data from Morningstar, 1,222 mutual funds held an ETF as a component of their portfolio in 2016, the most recent period for which data is available. The median size of the ETF holdings were 4.5% of the mutual fundโ€™s total assets under management.

In 2006, only 595 mutual funds held an ETF, comprising 1.2% of the assets.

While the number of mutual funds with ETF positions doubled over the past decade, those are still the minority: there were more than 9,000 U.S. mutual funds in 2015, according to the 2016 fact book put out by the Investment Company Institute. The category held $15.7 trillion in assets.

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