When the 'weak hands' sell they often buy back at a cheaper rate with more coins.
This is most definitely true. Perhaps not for all of them but this 'weak hand' does it often.
Until they get caught in a bear trap... Then they are empty hands.
I know a few people who were selling and buying back cheaper, and managed to make gains for a while. They were doing okay at first, but they got caught off guard when price made a major rally, and ended up buying back in at a loss. Now those guys are currently holding less coins than if they had just held...
Basically I think trading is great if you really know what you are doing and can completely detach yourself from your emotions. But I don't know anyone who can actually do this, so I tend to advise my friends to buy and hold...