A lot of people advise to sell during the bull runs and buy during the dips. This is in my opinion a good strategy but not the best. There's more money to be made. Every now and then there are these panic sells. And of course you should buy the crap out of it during these panic sells. But you should sell too in my opinion. Immediately after the 'bad' news causing these panic sells. Why? Because you can buy back lower. So more profit :D