You should really just have it in your decision making about when you buy where you are willing to sell, and how much you are willing to lose before selling. so if I buy $1k of ETH, i should know if I'm just day trading that if it hits $1200 i'm selling out, and waiting for it to dip back down, and if it goes below $800, then Im also limiting my losses. Then you just keep same strategy for each buy & sell you do, and if you just sold at $1200, don't buy back in when it goes to $1300, it'll dip back down to like that original $1k level. It's all cyclical, can't get caught up in the fomo but instead play the cycle game.