Well most in the community are doing the same, They would sure buy on an All time low and sell on the All time high, Rinse and repeat, Very simple strategy for a hodler, But there are some who surely risk they even sell on an ATL because they only believe that the price will surely drop, Well I really think there are no other system on how you can properly Buy and sell on the market of Cryptocurrency.
I totally agree with you mate. Simple strategy of buy coins at low price and sell coins at high price. But we can't predict totally which coins are very promising and that can assure you that it will pump in the future. Investment in cryptocurrency is very risky. Sometimes you can be panic of what had happened in the crypto market with your coin that's why sometimes you will do panic selling.