82 Percent Of All US Actively Managed Funds And Over 90 Percent Of Actively Managed US Equity Funds Trailed Their Benchmarks Over 15 Years

From The Wall Street Journal, "Indexes Beat Stock Pickers Even Over 15 Years: New data show that 82% of all U.S. funds trailed their respective benchmarks over 15 years" by Daisy Maxey and Chris Dieterich:

Most actively managed U.S. stock funds were beaten by their market benchmarks over the past decade and a half, a record of underperformance that helps explain why stock pickers are losing billions of dollars in assets each month to low-cost passive investments that track indexes.

Over the 15 years ended in December 2016, 82% of all U.S. funds trailed their respective benchmarks, according to the latest S&P Indices Versus Active funds scorecard. This was the first year that the analysis included 15 years of data, helping smooth out periods of volatility that can affect the performance of active managers.***

Source: The Wall Street Journal

Among more than a dozen categories tracked, 95.4% of U.S. mid-cap funds, 93.2% of U.S. small-cap funds and 92.2% of U.S. large-cap funds trailed their respective benchmarks, according to the data.