Question: how do index funds (or any kind of stock, really... in fact this question isn't really about index funds) "pull in the rest"? Do you actually manage to sell them when they're high and buy when they're low again? Or do you get stocks with dividends and just make money using the dividends? Obviously merely possessing stock of high value is kind of moot if it doesn't turn into cash somehow, so I'm curious how people usually do this. (I don't know much/anything about finance.)