Now bitcoin is growing very fast and it must end sometime. Most likely something like 2017 will happen. Therefore, if I were you, I would not sell all bitcoin, but part of it needs to be sold while its prices are so high.
^ all depends on the needs of the holders. if you really need funds then it is fine to sell the Bitcoin you have, but if you don't need fast funds then you don't need to sell Bitcoin, and we recommend that HODL until the price is really high.