Read this 

The issue with when a top forms and btc starts to begin its descent is that altcoins typically drop incredibly fast first without much warning - unlike btc whereby it drops but you'll get a few weeks where it rallies back up and creates lower highs

After that initial drop everyone is taken by suprise in altcoins, they typically dont gey anywhere near their high again 

This leaves people with the feeling that they cant take profits, even if theyre concerned the top may be in, because their portfolio has dropped significant already, its almost too painful to press the sell button, because all they can think about was how they were 50-100% richer 2-3 weeks ago.

And so begins the painful process of holding all the way back down