What if, you buy the @$1 then you sell it @$2 then the price keeps increasing to @$5 then stable for a month between $4-$5 because stable for a month now you decide to buy it @$4 because you think the price will hit $5 again even more, but after you buy it the price is dumped to $0,5

This is only a simple example, the point is crypto is unpredictable, you can make such a plan but it's hard for it to happen, because if easy we would see so many rich people in the crypto world.