Even you make it look very simple, I need to remind people that to make a stable profit from those is require skill in timing and reading market as well. Yes, it's safe because you allowed having a exist as become a holder but don't let that fool you.
Any trading strategy needs to be careful and certainly still can not avoid the risk if the market suddenly falls. Before trading I always spend a lot of time studying and analyzing because if I feel the market is good, I will choose to invest more but if the market is not stable, I will wait patiently. I am not in a hurry to trade because every decision I make will greatly affect profit.