Sometimes is a defensive thought, sometimes its an offensive one. I'd never sell it all, but converting some to another tangible asset has its merits.
I think it is worth taking a few profits along the way.
I think it is very interesting to sell about 1-10% when you reach 1000-10000% profits.
Then you can reduce a lot of your invested capital, reducing your risks and you will fell better when the price crashes again.