The flow of money from actively managed funds to index-trackers is one of the dominant themes in finance right now.  US exchange-traded funds now have close to $2.4 trillion in assets, according to the Investment Company Institute. Actively managed funds, in contrast, have been losing assets at a fast clip, with active equity funds seeing close to $150 billion in outflows so far in 2016. Hedge funds, meanwhile, continue to struggle. There has been a net $77 billion outflow from the hedge fund industry so far this year, according to eVestment. Performance, or the lack thereof, is at the heart of this....