A very big and controversial question indeed. Majority of bounty hunters find it very difficult to and sometimes contemplate whether to sell all the altcoins they have attained to buy bitcoin or hodl the altcoins as they are. This strategy is only valid if you are no longer interested in short term investment of money or even day trading. If you want to continue day trading, then it is better not to sell your altcoins as bitcoin is not a good choice when it comes to that of the day trading