Thanks for your experiences but some things are difficult to perform
the cycle is a cycle on ideal. If everyone could make it perfect, then the market will no longer balance
for example: Sell high at the right time and buy low at the right time, It is difficult to make. We fear that when selling coins don't have a chance to buy
I think if you can check market of BTC, you can see increase and decrease of coin, but you don't sell and buy at the right time, Currently, BTC unstable and hard to guess. You also need to have good luck factor.