ETFs are again beating mutual funds, here's why

Traders work on the floor of the New York Stock Exchange.
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While most investors look at mutual fund and ETF prices as a gauge of success, flows — the money going in and out — is sometimes a better indicator of investor sentiment. Despite the market fluctuations, it was another big year for ETFs in 2015: Money flowed into equity and bond ETFs, while money flowed out of mutual funds.