[kgwgk]

To make money you don't need to "Guess the future" in an absolute sense, you just need to "guess" better than the rest of the market participants.

When there is a majority buying/selling all the shares in block without any consideration to the differences in liquidity and fundamentals between stocks it may be easier to find opportunities than when everyone buys and sells individual stocks. (But one could also say that the average stock-picker is so bad that having more active investors actually increases the gain for the talented ones rather than pressuring profits due to competition).