The market's performance this year has surpassed that of most professional money managers. In fact, this is the worst (relative) year in three decades for professionals (see post here, The Reformed Broker). The level of competition and the high level of fees prevent meaningful outperformance. The result -- a large influx of capital into index funds.
Dolvin, Steven D., "More Evidence for Efficient Markets" (2014). All Chapters. 121.