[bitadder]

The problem isn't always knowing what to buy, but when to sell. For some who don't have the time of researching and rebalancing an index fund or ETF that does it for you is a good value prop.

Example where that strategy might run into problems - hindsight is 20/20: https://pbs.twimg.com/media/EH6la6VWoAIC0cM?format=jpg&name=...

[swinglock]

Index funds don't try to time the market. Which ETFs are you thinking about? Hedge funds?